INDUSTRIAL AND PRODUCTION ENGINEERING

2017-02-06T06:40:00.002-08:00

Supply-chain-management by sunil chopra,,,,

2013-04-10T09:06:00.001-07:00

Excel Problems

1. Mr. Smith, an avid reader, must decide on which books to take with him during a long flight. Mr. Smith will use his carryon bag which can hold a maximum of 20 pounds. Mr. Smith has attached a satisfaction index for each book, based on a 5-point scale (1 = low satisfaction, 5 =high satisfaction), as shown below.

Book Satisfaction Index Weight (lbs.)

Marketing 4 4

History 5 3

Statistics 1 3

Management 3 5

Finance 3 4

Economics 2 3

Excel 5 4

Access 4 5

Which books should Mr. Smith take with him on the flight to maximize his satisfaction index?

2. Six products are currently waiting processing on a single machine. The machine is available today for a maximum of 25 hours. The processing time per hour for each product along with the profit contribution per product is show below.

Product Profit Contribution Processing Time (Hours)

A $55 5

B $70 4

C $45 6

D $60 5

E $50 3

F $65 6

Which products should be processed to maximize the total profit contribution?

3. Refer to question 2. Assume that the following conditions must be met:

a) We want to ensure that exactly one of these products: A, B, or C must be processed.

b) We want to ensure that if product E is processed then product F must be processed?

Which products should be processed to maximize the total profit contribution?

4. A decision maker is provided with 5 different potential projects and must determine which projects to choose. The projects require different amounts of capital and different expected net present values (NPV) over the next three years. Determine which set of projects should be selected in order to achieve the maximum net present value if the decision maker has $150,000 available for investment each year.

NVP Capital Required (in $000s)

Project (in $000s) Year 1 Year 2 Year 3

1 140 70 20 25

2 180 85 40 15

3 120 60 20 20

4 80 30 30 15

5 200 50 15 10

5. Refer to problem 4. Determine which set of projects should be selected in order to achieve the maximum net present value if the following two conditions must also be met:

a) If project 1 is selected, then project 2 must be selected, and vice versa.

b) Since projects 4 and 5 require outsourcing various operations, the decision maker wants at most one of these projects to be included in the solution and not both.

6. A company currently has two factories: F1 and F2, and three retail outlets: R1, R2, and R3. The shipping costs per unit along with the monthly capacity and demand requirements are summarized below:

Shipping Cost Per Unit

R1 R2 R3 Supply

F1 $3 $2 $4 100

F2 $1 $3 $5 200

Demand 100 100 200

The firm has decided to build a new factory to expand its productive capacity. The two sites being considered are Philadelphia and Pittsburgh. The estimated shipping costs for the new factories along with their estimated fixed cost and production capacity are summarized below:

R1 R2 R3 Supply Fixed Cost

Philadelphia $2 $4 $3 100 $20,000

Pittsburgh $3 $5 $2 100 $25,000

Which of the new locations will yield the lowest cost in combination with the existing factories and retail outlets?

7. A company produces four products each of which must undergo assembly, inspection, and packaging. The information below summarizes the hours required for each operation by each product, the total hourly capacity for each operation, and the fixed cost incurred by each product if it is produced.

Hours Required

Available

Operation Product 1 Product 2 Product 3 Product 4 Hours

Assembly 3 4 5 4 500

Inspection 2 1 3 2 300

Packaging 1 1 2 2 200

Fixed Cost $1100 $1000 $900 $850

Each unit of product 1 sold will contribute $60 to profit, and each unit of products 2, 3, and 4 contributes $65, $70, and $55, respectively. What is the optimal product mix?

8. A city is reviewing the location of its fire stations. The city is made up of a number of districts, as illustrated below. A fire station can be placed in any district and is able to handle the fires for both its neighborhood and any adjacent neighborhood. The objective is to minimize the number of fire stations used.

9. An investor is considering 7 different stocks: A, B, C, D, E, F, and G. The expected annual return for each stock is provided as follows:

Annual

Stock Return

A 9.5%

B 8.0%

C 7.0%

D 10.0%

E 8.0%

F 9.0%

G 10%

The investor has imposed the following restrictions regarding the composition of the portfolio:

· the portfolio must include exactly one of the following stocks: either A or B.

· if stock B is selected, then stock F must also be selected.

· if stock D is selected, then stock E must be excluded.

Which stocks should be included in the portfolio to maximize annual return?

10. A company is considering producing 8 different products for the upcoming holiday season. The profit contribution per product is illustrated below:

Product Profit ($)

1 10

2 12

3 7

4 15

5 8

6 9

7 13

8 11

The marketing manager has imposed the following restrictions on the production mix:

· since products 1, 2, and 3 are electronic gadgets, at least two of these products must be in the production mix..

· since products 4 and 5 are kids oriented, the production mix must include no more than one of these products.

· if product 7 is included in the mix, then product 8 must be included, and vice versa.

Which products should be included in the mix to maximize profit?

11. A developer wishes to expand an office complex and needs to determine how many small, medium, and large offices to include in the expansion. Each small office requires 400 square feet, each medium office requires 700 square feet, and each large office requires 1200 square feet. The current square footage available for expansion is 35,000 square feet. The developer expects to pay $10,000 for each small office, $20,000 for each medium office, and $35,000 for each large office. The developer wishes to limit his expenditures to $500,000. How many of each type of office should be built if the following goals, stated in no particular order, must be met?

Goal 1: The expansion should include approximately 6 small offices.

Goal 2: The expansion should include approximately 11 medium offices.

Goal 3: The expansion should include approximately 15 large offices.

Goal 4: The expansion should consist of approximately 35,000 square feet.

Goal 5: The expansion should cost approximately $500,000.

12. Consider the following linear programming g problem:

Max: 500A + 700B

Subject to:

2A + 3B ≤ 35 (assembly hours)

3A + 5B ≤ 40 (Machine hours)

Reformulate and solve this problem as a goal programming problem if the following goals, stated in no particular order, must be met?

Goal 1: Produce at least 15 units of each product.

Goal 2: Avoid overtime in the assembly and machine departments.

Goal 3: Achieve at least $100,000 in profit.

13. Consider the following linear programming problem:

Max: 500A + 700B

Subject to:

2A + 3B ≤ 35 (assembly hours)

3A + 5B ≤ 40 (Machine hours)

Reformulate and solve this problem as a goal programming problem if the following goals, with their associated weights, must be met?

Goal 1: Produce at least 15 units of product A; Weight 15

Goal 2: Produce at least 15 units of product B; Weight 15

Goal 3: Minimize overtime in assembly department; Weight 25

Goal 4: Minimize overtime in machine department; Weight 25

Goal 5: Achieve at least $100,000 in profit; Weight 20

14. Consider the following linear programming g problem:

Max: 500A + 700B

Subject to:

2A + 3B ≤ 35 (assembly hours)

3A + 5B ≤ 40 (Machine hours)

Reformulate and solve this problem as a goal programming problem if the following prioritized goals must be met?

Goal Priority

Product at least 15 units of each product P₁

Minimize overtime in assembly and machine departments P₂

Achieve at least $100,000 in profit P₃

15. A marketing manager is considering the following advertising media to promote a new

product.

Type Audience Reached/Ad Cost/Ad Maximum No. of Ads

TV 50,000 $3000 10

Radio 25,000 $1000 15

Newspaper 10,000 $500 30

The marketing manager has established the following goals, stated in no particular order, for the advertising campaign:

Goal 1: Reach at least 500,000 individuals

Goal 2: Limit the total spending to $150,000

Formulate and solve this goal programming problem.

16. A marketing manager is considering the following advertising media to promote a new

product.

Type Audience Reached/Ad Cost/Ad Maximum No. of Ads

TV 50,000 $3000 10

Radio 25,000 $1000 15

Newspaper 10,000 $500 30

The marketing manager has established the following goals and weights:

Goal 1: Reach at least 500,000 individuals; Weight 40

Goal 2: Limit the total spending to $150,000; Weight 60

Formulate and solve this goal programming problem.

17. Set up and solve the following nonlinear programming problem using Excel:

Max: 10X₁ + 15X₂ + 5X₃ + 2X₃³

Subject to

X₁ + X₂ + X₃ ≤ 50

2X₁ + 3X₂ ≤ 150

X₁, X₂, X₃≥ 0

18. Set up and solve the following nonlinear programming problem using Excel:

Max: X₁ + 2X₂ + 3X₁X₂+ 5X₃³

Subject to

X₁ + X₂ + X₃ ≤ 75

X₁ + X₂ ≥ 15

2X₁ + 2X₃ ≤ 40

X₁, X_2,X₃ ≥ 0

19. Set up and solve the following nonlinear programming problem using Excel:

Max: (X₁ – 5)² + (X₂ – 7)²

Subject to

X₁ ≤ 15

X₂≤ 15

X1 + X2 ≥ 10

X₁, X₂≥ 0

20. Consider the following profit expected from each dollar (X_i) spent in the following advertising media:

Medium Profit

TV 0.0005X_i³

Radio 0.0025X_i²

Newspaper 0.01X_i

How should the advertising budget be allocated if the company wants to spend at least $1000 on each medium without exceeding its $10,000 budget?

Supply-chain-management by sunil chopra,,,,CHAPTER 5

2013-04-10T09:05:00.001-07:00

CHAPTER 5

Discussion Questions

How do the location and size of warehouses affect the performance of a firm such as Amazon.com? What factors should Amazon.com take into account when making this decision?

The location and size of Amazon’s warehouses have a direct bearing on how responsive and efficient they can be. At one time Amazon ran their on-line bookstore out of one warehouse in Seattle; this warehouse was small by today’s standards and was unable to keep up with peak demand. Amazon has since added other geographically distributed warehouses that hold the items with steadier demand. The dispersion of warehouses allows Amazon to ship from closer to the customers and the stocking of items with more even demand allows for a higher service level at a reasonable cost.

Amazon should consider what regions are underserved by the current network of warehouses and where it is most economical to locate the next warehouse, effectively balancing their efficiency and responsiveness with their strategy.

How do import duties and exchange rates affect the location decision in a supply chain?

Tariffs refer to any duties that must be paid when products are moved across international, state, or city boundaries. If a tariff is excessive, it provides a strong disincentive to do business across borders with entities in that area. The classic workaround to a high tariff is adding a location inside the area. Some regions have developed trade agreements that limit or eliminate the tariff on goods.

Exchange rates specify how much one currency is worth in terms of another. As one currency gains against another, it may be beneficial to add shift production to the area using the devalued currency. This makes the goods more affordable for the population. Companies with flexible production capabilities can shift some production from area to area depending on the buying power of local markets.

What are different roles played by production facilities within a global network?

The different strategic roles for facilities in a global network are as follows:

Offshore facility: low-cost facility for export production. This is strictly a low-cost producer for an export market
Source facility: low-cost facility for global production. This facility is also viewed as a low-cost provider, but provides output for the entire global network.
Server facility: regional production facility This facility supplies the market in the country where it is located
Contributor facility: regional production facility with development skills. This facility serves the market where it is located but is also responsible for customization that increases salability in that country.
Outpost facility: regional production facility built to gain local skills. This facility plays the role of a server facility but more importantly, it obtains access to knowledge or skills that exist in that region.
Lead facility: facility that leads in development and process technologies. This facility creates new processes, technologies and products for the entire network.

Amazon.com has built new warehouses as it has grown. How does this change affect various cost and response times in the Amazon.com supply chain?

Logistics and facility costs incurred within a supply chain change as the number of facilities, their location, and capacity allocation is changed. As Amazon has added warehouses, their logistics, inventory and facility costs have changed. An increased number of warehouses increases that fixed cost but can be exploited to reduce transportation costs. These potentially fall if the warehouses are spread throughout a distribution area, which increases responsiveness at a similar cost or maintains responsiveness at a reduced cost. Inventory costs also change with an increased number of warehouses; Amazon is holding more total inventory and can take advantage of pooling to reduce quantities of some items.

McMaster-Carr sells maintenance, repair, and operations equipment from five warehouses in the United States. WW Grainger sells products from more than 350 retail locations, supported by several warehouses. In both cases, customers place orders using the Web or on the phone. Discuss the pros and cons of the two strategies.

WW Grainger has the more responsive network; a customer with a critical repair need can drive to a local retail location to pick up the necessary part. McMaster Carr’s network is less responsive; critical supplies would be scheduled for overnight delivery in all likelihood. WW Grainger has the greater facility cost since it has more locations, although the retail facilities provide a presence that doubles as a marketing tool not enjoyed by McMaster Carr. McMaster Carr’s facility expense is much lower and their network model shifts the transportation cost more fully to the customer. A WW Grainger customer travels the last mile to pick up an order, but Grainger must ship from their warehouse to the retail locations.

Consider a firm such as Dell, with very few production facilities worldwide. List the pros and cons of this approach and why it may or may not be suitable for the computer industry.

The advantage for Dell’s network design is lower facility costs; they can locate in just enough countries to avoid tariffs and mitigate some of their exchange rate and demand risk. The disadvantage for Dell is the lack of responsiveness this adds to their system. A customer has no expectation of zero flow time, so they know as they enter the transaction that they must wait for their PC. Shipping from one of the production facilities adds to the delay, which is highly visible on Dell’s or the package carrier’s web site. The shipping costs might also be a concern for some customers, but the value to shipping cost ratio is so high that these costs seem like small potatoes in comparison to the total invoice.

Consider a firm such as Ford, with more than 150 facilities worldwide. List the pros and cons of having many facilities and why it may or may not be suitable for the automobile industry.

Automakers often use a multiplant strategy to create server facilities. These server facilities provide product for the market where they are located, thereby taking advantage of tax incentives, local content requirements, tariff barriers, and high logistics costs. This can be a good strategy if market demand exists for your product; when demand drops, the producer is left with expensive excess capacity. If the facilities are flexible, production of popular models can continue to prepare product for export. If facilities are inflexible or all sales are flat, then the producer must bear the cost or shed assets.

Excel Problems

1. The following network describes the hourly volume of traffic that can flow between various communities in Dover County. Assume traffic can flow in both directions between each community at the same rate. What is the maximum flow of cars between Communities 1 and 6 in one hour?

Formulate this problem as a linear programming problem.

Answers:

Maximize: X₆₁

Subject to:

Balance of flow constraints:

Node 1: X₆₁-X₁₂-X₁₃ = 0

Node 2: X₁₂-X₂₄-X₂₅ = 0

Node 3: X₁₃-X₃₄-X₃₅ = 0

Node 4: X₂₄+X₃₄-X₄₆ = 0

Node 5: X₂₅+X₃₅-X₅₆ = 0

Node 6: X₄₆+X₅₆-X₆₁ = 0

Arc capacity constraints:

0 ≥ X₁₂ ≤ 500

0 ≥ X₁₃ ≤ 400

0 ≥ X₂₄ ≤ 600

0 ≥ X₃₄ ≤ 400

0 ≥ X₂₅ ≤ 200

0 ≥ X₃₅ ≤ 600

0 ≥ X₄₆ ≤ 100

0 ≥ X₅₆ ≤ 500

0 ≥ X₁₆ ≤ 100,000

2. Refer to problem 1 and its associated Excel solution shown below.

What values would you enter in the Solver Parameter dialog box for the Excel

spreadsheet model?

Set Target Cell:

By Changing Cells:

Subject to the Constraints:

Answers:

Set Target Cell: B21

By Changing Cells: B4:G9

Subject to the Constraints: B25:B30 = D25:D30; B4:G9 ≤ B14:G19

3. Refer to problem 2 and its associated Excel spreadsheet model.

a. What equation should be entered in cell H4?

b. What equation should be entered in cell B10?

c. What equation should be entered in cell B25?

Answers:

a. =SUM(B4:G4)

b. =SUM(B4:B9)

c. =B10 – H4

4. Bob Jenkins needs to drive from City 1 to City 7 and would like to find the shortest route between the two. The road system with the distance in miles between cities is shown in the network below. What cities should he travel through to minimize his distance?

Refer to the following Excel spreadsheet model.

What values would you enter in the Solver Parameter dialog box for the Excel

spreadsheet model?

Set Target Cell:

By Changing Cells:

Subject to the Constraints:

Answers:

Set Target Cell: B23

By Changing Cells: B4:H10

Subject to the Constraints: B27:B33 = D27:D33

5. Refer to problem 4 and its associated Excel spreadsheet model.

a. What equation should be entered in cell B23?

b. What equation should be entered in cell B27?

c. What equation should be entered in cell I4?

Answers:

a. = SUMPRODUCT(B4:H10,B15,H21)

b. = B11 – I4

c. = SUM(B4:H4)

Supply-chain-management by sunil chopra,,,,CHAPTER FOUR

2013-04-10T09:03:00.001-07:00

CHAPTER FOUR

Discussion Questions

1. What differences in the retail environment may justify the fact that the fast-moving consumer goods supply chain in India has far more distributors than in the United States?

India is a land of shopkeepers selling to over a billion consumers. India is becomingly increasingly Westernized, but it will be quite a while (if not forever) before shopkeepers are supplanted by large retailers. The sheer volume of small store owners requires a large number of distributors to service them. The younger generation in India, particularly the IT rich areas of Bangalore and Chennai, have far higher disposable income than the older generation and the rest of the country. These young workers have very different retail habits and are causing changes in India’s shopping and supply chain needs. Poor infrastructure, although not entirely a retail concern, is another reason why India may need far more distributors than in the U.S.

2. A specialty chemical company is considering expanding its operations into Brazil, where five companies dominate the consumption of specialty chemicals. What sort of distribution network should this company utilize?

If the expansion into Brazil is merely a sales operation, then distributor storage with last mile delivery is the best network design. If the expanded operations include manufacturing capabilities, then manufacturer storage with direct shipping is a strong possibility. Given the nature of the product, package carrier delivery is not an option and retail storage with customer pickup is out of the question since this is a B2B scenario. In-transit merge would be an option only if the manufacturer established a network of plants in Brazil, perhaps focused factories relatively close to each customer.

The chemical company has only five customers to serve; it would not require too large an investment in logistical infrastructure to effectively serve all five without intervention by a distributor. Their short supply chain would be easier to coordinate due to the stable demands and information sharing that is possible in a B2B scenario.

3. A distributor has heard that one of the major manufacturers from which it buys is considering going direct to the consumer. What can the distributor do about this? What advantages can it offer the manufacturer that the manufacturer is unlikely to be able to reproduce?

The two supply network designs that the distributor can propose to counter the manufacturer’s proposal are the distributor storage with package carrier delivery and the distributor storage with last mile delivery. Both of these counter-proposals offer higher order visibility for the customer while having simpler information infrastructure than with manufacturer storage. The response time for both is excellent, and the customer experience is also superior to the direct model. If the manufacturer is trying to provide excellent customer service, the increased costs in transportation and potentially higher levels of inventory may be acceptable tradeoffs.

4. What types of distribution networks are typically best suited for commodity items?

Commodity items are available from many sources and customers expect them to be delivered quickly; if a supply chain can’t be responsive, the customers will move on to the next source. A distribution network designed for retail storage with customer pickup achieves quick response for high demand, low variety products. Other commodity products can be effectively distributed using distributor storage with last-mile delivery, which is also suited for high demand, quick response products.

5. What type of networks are best suited to highly differentiated products?

The networks that are best suited to highly differentiated products are the manufacturer storage with direct shipping and the manufacturer storage with in-transit merge. Both approaches have the ability to aggregate inventories and postpone product customization, which would help support a wider variety of products.

6. In the future, do you see the value added by distributors decreasing, increasing, or staying about the same?

It is doubtful that value added by distributors will decrease over time; the nature of competition in all areas would suggest that distributors that add less value would be winnowed out. It is more likely that distributors will be asked to do more or may volunteer to do so as a means of differentiating themselves from the competition.

7. Why has e-business been more successful in the PC industry compared to the grocery industry? In the future, how valuable is e-business likely to be in the PC industry?

The PC industry is selling a highly customized product that is purchased on a per-household basis, less routinely than the commodity products that make up groceries. A company like Dell can leverage the Internet as a marketing and distribution tool to advertise new capabilities and options before bricks and mortar retailers can. Dell also removes whatever intimidation (or frustration) factor might be experienced by conversing with in-store sales representatives. Computers have a very high value to shipping cost ratio, so the increased shipping costs when compared to a traditional store are negligible. Groceries have a much lower ratio; although in-store shoppers are incurring costs to pick up their groceries, those costs are hidden in comparison to the delivery charge on an itemized bill from Peapod.

E-business will continue to be a valuable tool in the PC industry; none of the advantages currently being enjoyed by Dell and Gateway are likely to change significantly.

8. Is e-business likely to be more beneficial in the early part or the mature part of a product’s life cycle? Why?

E-business is more likely to be more beneficial in the early part of a product’s life cycle. E-business strengths include flexible pricing, promotions, and product portfolios and greater speed in disseminating product information. Later in the life cycle, a product is likely to be a commodity, which doesn’t play to the strengths of this channel.

9. Consider the sale of home improvement products at Home Depot or a chain of hardware stores such as True Value. Who can extract the greatest benefit from going online? Why?

Both entities and other hardware companies like Ace are already on-line. An article titled “Home Depot’s Self-Improvement – Company Business and Marketing” by Eric Young in The Industry Standard, September 11, 2000, indicates that Home Depot is the last major player to go on-line, but brings the deepest pockets. Those of us that have stood in line with the contractors realize that many of Home Depot’s items are ill-suited to a web enterprise and the clientele is equally ill-suited. Contractor sales are such a significant portion of Home Depot’s sales in comparison with the mix at True-Value, that it is likely that True-Value will ultimately benefit more from an e-commerce division.

The article goes on to say,

“Each chain is employing a slightly different e-commerce strategy. Whereas Home Depot wants its site to replicate its merchandise mix, True Value limits the number of items it offers online. For example, at True Value, Net shoppers won't find products most people need in a hurry, such as toilet-tank fix-it kits. "You're not going to wait three days to have it shipped so you can stop the water from dripping into your neighbor's apartment," says Neil Hastie, CIO at TrueValue.com.

Ace Hardware, meanwhile, thinks bigger is better. Its site offers almost everything in its stores, plus about 15,000 additional products. Ace's supplementary online offerings are a windfall from its investment in OurHouse.com, a Web-based home improvement site that handles Ace's online sales. The two companies split online revenues. Ace joined forces with OurHouse to get a leg up in e-commerce. "We didn't want to be left in the starting gate," says Ken Nichols, a retail operations vice president for Ace.

Waiting in the wings is Lowe's, the nation's second-largest home improvement chain. Like Home Depot, Lowe's wants to expand its online presence but is approaching e-commerce slowly. Beginning in October, the retailer will offer a wide selection in a limited number of categories, such as hand tools and appliances. Lowe's will deliver Net orders directly to buyers or to the store closest to the customer, again like Home Depot.

Meanwhile, Internet-only retailers are scrambling to win over customers, vowing to compete against offline chains in price and selection. CornerHardware, for example, says it currently has 125,000 products available -- three times the number available at an average Home Depot store.

The pure Internet players acknowledge that they don't have the brand recognition of Home Depot. But they hope to build their brands before Home Depot and the other brick-and-mortar stores establish a strong online presence. Still, it's not clear that any are benefiting from first-mover advantage. Already two Net pure-plays -- Hardware.com and HomeWarehouse.com -- have gone under.”

10. Amazon.com sells books, music, electronics, software, toys, and home improvement products online. In which product category does e-business offer the greatest advantage compared to a retail store chain? In which product category does e-business offer the smallest advantage (or a potential cost disadvantage) compared to a retail store chain? Why?

Amazon’s greatest e-business advantage comes from book sales; they are able to list millions of book titles that a physical store cannot possibly carry on their shelves. Cost advantages for Amazon are few and far between; the item price to shipping cost ratio for books, music, and software is not as high as most consumers would prefer. Amazon certainly has no cost advantage with music and software. Both are readily sold over the Internet; it would behoove Amazon to partner with another Seattle-area company to make this the norm. Electronics, hardware, and even toys are products that most consumers would like to experience before making a selection. Any cost advantage Amazon might have in these sectors may be overshadowed by an inability to hold the item on-line.

11. Why should an e-business such as Amazon.com build more warehouses as its sales volume grows?

Amazon initially tried to run their entire book business with no warehousing facilities, instead relying on other distributors to carry their entire inventory. Next, Amazon ran their business out of a single warehouse in Seattle and discovered it wasn’t feasible; the trade-off of responsiveness and cost was causing excessive delays in getting products to customers. Now Amazon uses a hybrid of these two systems, carrying items that it knows will sell in its own warehouses and letting others carry items that have greater demand uncertainty. As Amazon’s business grows, it should continue to establish warehouses to spread its facilities closer to pockets of new customers, thus achieving better levels of responsiveness while still maintaining its cost advantage.

Supply-chain-management by sunil chopra,,,,CHAPTER THREE

2013-04-10T09:02:00.000-07:00

CHAPTER THREE

Discussion Questions

How could a grocery store use inventory to increase the responsiveness of the company’s supply chain?

The logistical driver of inventory encompasses all raw materials, work in process, and finished goods within a supply chain. A grocery store can be more responsive in the eyes of its customers if it offers a broader variety of SKUs and/or maintains a greater quantity of each SKU. A greater quantity of each SKU is problematic for highly perishable items like produce, meat, fish, etc. For these items, a grocery store supply chain should be set up to permit frequent orders so that freshness is ensured and a stockout situation won’t exist for a significant length of time. A grocery store supply chain should use historical demand patterns for seasonal items to relieve stress on all members and provide customers with product during peak demand periods.

How could an auto manufacturer use transportation to increase the efficiency of its supply chain?

Transportation, a logistical driver, entails moving inventory from point to point in the supply chain. The trade-off in transportation is between the cost of transportation and the speed at which product is transported. Slower modes of transportation reduce cost, but could be a reasonable approach if suppliers are co-located with the assembly operations. If the supply chain is designed in such a way, and assembly operations are located with proximity to markets, then the supply chain can be run cheaply without holding too much inventory in transit.

How could a bicycle manufacturer increase responsiveness through its facilities?

Facilities, another logistical driver, are the actual physical locations in the supply chain network where product is stored, assembled, or fabricated. A facility that is designed to be flexible can respond quickly to market demands by retooling to produce different models or products, whereas a dedicated facility cannot. Locating a facility close to the market will increase responsiveness at the cost of decreased economies of scale that might be achieved with a centralized location. A facility that is under capacity will be less responsive than a facility that is appropriately sized or has excess capacity.

How could an industrial supplies distributor use information to increase its responsiveness?

Information is a cross-functional driver and consists of data and analysis concerning facilities, inventory, transportation, costs, prices, and customers throughout the supply chain. Information serves as a connection among all members of the supply chain and operates within each member to facilitate internal operations. Accurate information can improve responsiveness by helping an industrial supplier better match supply and demand. Information that is gathered farther down the supply chain can be transmitted instantaneously and accurately to the supplies distributor. Instead of waiting for a human to call or FAX an order, the distributor can replenish inventory to the necessary levels or provide what is needed to fill the order as it is realized.

Motorola has gone from manufacturing all its cell phones in-house to almost completely outsourcing the manufacturing. What are the pros and cons of the two approaches?

Sourcing is the set of business processes required to purchase foods and services. These decisions are crucial because they affect the level of efficiency and responsiveness that Motorola can achieve. The Motorola production system for their line of pagers was hailed as a breakthrough in mass customization, so it was somewhat surprising when Motorola outsourced cell phones.. Sourcing decisions should be made based on the total supply chain surplus; if a third party can help the chain achieve greater surplus, then the function is a prime candidate for outsourcing. Motorola was willing to give up some control and possibly some of its design talent and assembly expertise because it felt that the supplier could provide product of an appropriate level of quality with the responsiveness necessary. Products and services that are outsourced are rarely brought back in-house and should never be tied too closely to the outsourcing party’s core competency.

How can a home delivery company like Peapod use pricing of its delivery services to improve its profitability?

Pricing is the process by which a firm decides how much to charge customers for its goods and services. Pricing affects the customer segments that choose to buy the product as well as the customer’s expectations. Peapod can use everyday low pricing of its products to ensure stability in the supply chain, but can influence demand by varying the delivery charges. For example, by establishing a minimum order amount of $50 and charging $10 to deliver an order under $75, Peapod provides an incentive for a customer to pile on additional items to save on per unit shipping. An order over $100 incurs a delivery fee of $7, which is the lowest delivery charge for a residential customer.

Peapod also varies delivery charges by time of day; evening delivery times on weekdays and morning deliveries on Sunday within narrow windows cost an extra dollar, wider delivery windows are $1 less. The delivery latitude allows Peapod’s delivery drivers to schedule more efficiently thereby increasing profitability.

What are some industries in which products have proliferated and life cycles have shortened? How has the supply chains in these industries adapted?

The authors cite the example of running shoes increasing from five styles in the early 70s to almost 300 by the late 90s. Other products that have seen an explosion in variety include personal electronics, beverages, snack and prepared foods, entertainment, tires, and personal services.

Supply chains have leveraged information systems, recognized the need to collaborate on product and process design, and supply chain execution. The supply chain stance has shifted towards a partnership orientation from a focus on price negotiations.

How can the full set of logistical and cross-functional drivers be used to create strategic fit for a PC manufacturer targeting both time sensitive and price conscious customers?

The logistical drivers, facilities, inventory, and transportation, and the cross-functional drivers, information, sourcing, and pricing, must be used in concert to achieve the appropriate balance of efficiency and responsiveness for the supply chain to be successful. A PC manufacturer that wants to deliver product both quickly and efficiently can make cost and time trade-offs among these drivers to achieve their goals. These trade offs across drivers afford more flexibility but require constant vigilance as the trade-offs within each driver change. In addition, some drivers may be altered more easily, e.g., order quantity and transportation media, than other drivers, e.g., location and sourcing.

The trade-offs within each driver are summarized in the table:

Driver	More Responsive	More Efficient
Facilities	Multiple Plants Flexible Plants	Single Plant Dedicated Plant
Inventory	Higher Inventory	Lower Inventory
Transportation	Higher Speed	Lower Speed
Information	Accurate Real Time Transmission	Less Accurate Batched Transmission
Sourcing	Responsive supplier	Efficient supplier
Pricing	Differential Pricing	Everyday Low Pricing

Supply-chain-management by sunil chopra,,,,CHAPTER TWO

2013-04-10T09:00:00.001-07:00

CHAPTER TWO

Discussion Questions

How would you characterize the competitive strategy of a high-end department store chain such as Nordstrom? What are the key customer needs that Nordstrom aims to fill?

The Nordstrom web site states the following. Over the years, the Nordstrom family of employees built a thriving business on the principles of quality, value, selection, and service. Today, Nordstrom is one of the nation’s leading fashion retailers, offering a wide variety of high-quality apparel, shoes, and accessories for men, women, and children at stores across the country. We remain committed to the simple idea our company was founded on, earning our customers’ trust one at a time.

Nordstrom fills customer needs for high quality fashion merchandise and outstanding levels of customer service. Price is no object for the typical Nordstrom shopper.

Where would you place the demand faced by Nordstrom on the implied demand uncertainty spectrum? Why?

Implied demand uncertainty is demand uncertainty due to the portion of demand that the supply chain is targeting, not the entire demand. A high-end department store chain such as Nordstrom falls on the high end of the implied demand uncertainty scale. The fashion items that Nordstrom stocks have extremely high product margin, high forecast errors and stockout rates, and once the season is over, these items are sold at deep discounts at their Nordstrom Rack outlet stores.

What level of responsiveness would be most appropriate for Nordstrom’s supply chain? What should the supply chain be able to do particularly well?

Supply chain responsiveness takes many forms, including the ability to respond to a wide range of quantities, meet short lead times, handle a large variety of products, build innovative products, meet a high service level, and handle supply uncertainty. The Nordstrom supply chain must be highly responsive in the areas of handling highly innovative fashion products, customer response, and service level; they are effective in supplying well-heeled customers with merchandise and their return policy is legendary in the Pacific Northwest.

How can Nordstrom expand the scope of the strategic fit across the supply chain?

Scope of strategic fit refers to the functions within the firm and stages across the supply chain that devise an integrated strategy with a shared objective. By adopting an intercompany interfunctional scope strategy, Nordstrom will maximize supply chain surplus. Nordstrom can move in this direction by working with their suppliers as if they are actually owned by Nordstrom. Rather than viewing the supply chain as a zero-sum game of inventory cost minimization and profit maximization, Nordstrom must recognize that spreading the wealth and occasionally taking on more inventory than is optimal for them will result in improved customer service. The intercompany interfunctional scope of strategic fit requires more effort than the other approaches presented in this section; Nordstrom must evaluate all aspects of their supply web.

Reconsider the previous four questions for other companies such as Amazon.com, a supermarket chain, and auto manufacturer, and a discount retailer such as Wal-Mart.

Amazon.com focuses on cost and flexibility by providing books, music and a host of other household products at low prices. Customers place orders online and expect to receive purchases in a number of days. Customer orders are processed at central warehouses or are drop shipped from suppliers by mail or common carrier. For the most part, the implied demand uncertainty for Amazon.com is low as they cast such a wide net. Amazon.com’s supply chain must be responsive in terms of flexibility; they handle an incredibly diverse range of products. Amazon.com’s supply chain should be able to provide low prices wide variety and reasonable delivery schedules for its customers. In every link of the supply chain, Amazon.com must function on the cost-responsiveness efficient frontier in order to support its competitive strategy.

A supermarket chain focuses on cost and quality, with some specialty chains adding flexibility by carrying a broader range of products that may be targeted towards customers interested in organic products or ethnic cuisine. Implied demand uncertainty for a supermarket chain tends to be low; shoppers are typically repeat customers and have a constant demand level. The supermarket supply chain must be responsive by receiving produce quickly to ensure freshness and have a high service level. Supermarket supply chains tend to be well-established and can improve strategic fit by emphasizing speed to maintain freshness, hence perceived quality.

Auto manufacturers have extremely complicated supply chains that are increasingly focused on flexibility and lean operations. Implied demand uncertainty for auto manufacturers varies considerably by target market and manufacturer. Automotive supply chains among the big three in the United States have made great progress in the last decade and recognize that they must be responsive from a time and flexibility standpoint.

Wal-Mart’s supply chain is obsessed with cost and is facilitated by a low implied demand uncertainty, their impressive logistics system and their management information systems. Their supply chain is able to respond quickly to fill a wide variety of products to keep merchandise on Wal-Mart’s shelves. Wal-Mart’s level of coordination along the supply chain is excellent; it would be difficult to point out areas where true intercompany interfunctional scope of strategic fit has not been achieved. The sole supply chain criticism that surfaces is an occasional report that suppliers feel as if supply chain surplus is not shared equitably.

Give arguments to support the statement that Wal-Mart has achieved very good strategic fit between its competitive and supply chain strategies.

The best argument to support the statement that Wal-Mart has achieved very good strategic fit is their success as a company. Competition today is supply chain versus supply chain, not company versus company, so a company’s partners in the supply chain often determine the company’s success. Wal-Mart’s strategic focus on cost is evident in their competitive, product development, supply chain, and marketing strategy. Their marketing strategy of advertising every day low prices appeals to consumers and does not disrupt the supply chain by causing surges in demand. Visiting one of their big box stores reveals low-priced merchandise, both national and store brands, stacked from floor to ceiling without elaborate displays or decoration. Wal-Mart’s logistics and information systems are famous for coordinating their entire supply chain and allowing it to meet customer needs at minimal cost.

What are some factors that influence implied uncertainty? How does the implied uncertainty differ between an integrated steel mill that measures lead times in months and requires large orders and a steel service center that promises 24-hour lead times and sells orders of any size?

From a customer perspective, implied demand uncertainty increases when the customer’s range of quantity required increases, lead times decrease, variety of product increases, rate of innovation increases and required service levels increase. We also see high implied uncertainty attributed with high product margins, forecast errors above 40%, stockout rates above 10% and forced season-end markdowns. On the supply side we see increased supply uncertainty when the supply source has frequent breakdowns, unpredictable and low yields, poor quality, limited supply capacity, and evolving production processes.

For the steel mill that requires large orders and has lead times measured in months both the implied demand and supply uncertainty is less due to a better predictable capability and a better defined schedule for production. Due to the increasing number of sizes and the shorter response time associated with the steel service center, implied uncertainty is high.

What is the difference in implied uncertainty faced by a convenience store chain such as 7-Eleven, a supermarket chain, and a discount retailer such as Costco?

When customers go to a convenience store chain such as 7-Eleven, they go there for the convenience of a nearby store and are not necessarily looking for the lowest price. Implied demand uncertainty would be high as customers are looking for a variety of products and convenience versus cost and demand levels are hard to predict.

Low price is very important to customers of discount retailers such as Costco. This customer is willing to tolerate less variety and even purchase very large package sizes as long as the price is low. Customer demand can be more predictable and supply side needs are large and fairly stable.

What are some problems that can arise when each stage of a supply chain focuses solely on its own profits when making decisions? Identify some actions that can help a retailer and a manufacturer work together to expand the scope of strategic fit.

High inventories, poor quality, low customer service, increased returns are just a number of problems that occur when each stage of a supply chain focuses solely on its own profits. The trucking company requires full truck loads for delivery forcing the retailer to carry more inventory than wanted or needed. The supplier offers discounts to their buyers to maximize production but forcing the buyers to purchase in larger quantities than desired. This concept was very prevalent during the 1950s and 1960s as companies to minimize local costs and maximize their own profits.

Today, retailers and manufacturers have the opportunity to plan promotions jointly such as Wal-Mart and P&G. They can share sales information to determine customer trends. Joint product development opportunities are being explored throughout the supply chain between retailers, manufacturers and raw material suppliers.

Supply-chain-management by sunil chopra,,,, CHAPTER ONE

2013-04-10T08:54:00.000-07:00

CHAPTER ONE

Discussion Questions

1 Consider the purchase of a can of soda at a convenience store. Describe the various stages in the supply chain and the different flows involved.

When a customer purchases a can of soda at a convenience store, his purchase represents the end of a supply chain’s delivery of an item and the beginning of information regarding his purchase flowing in the opposite direction.

The supply chain stages include customers, retailers, wholesalers/distributors, manufacturers, and component/raw material suppliers. A customer’s purchase moves product towards the customer and dollars and information towards the retailer.

The retailer places an order from the wholesaler/distributor to replenish stock, thereby moving information back up the supply chain while moving product down the supply chain. As the order is filled, the retailer will move dollars back up the supply chain.

The wholesaler/distributor transmits information and dollars to the manufacturer who produces product and ships it down the supply chain to the wholesaler.

Finally (or initially, depending on your perspective) the manufacturer moves orders (information) and dollars towards suppliers in exchange for material flow into their production processes.

2 Why should a firm like Dell take into account total supply chain profitability when making decisions?

Dell realizes that their ultimate success lies with the success of their supply chain and its ability to generate supply chain surplus. If Dell was to view supply chain operations as a zero sum game, they would lose their competitive edge as their suppliers’ businesses struggled. Dell’s profit gained at the expense of their supply chain partners would be short lived. Just as a physical chain is only as strong as its weakest link, the supply chain can be successful only if all members cooperate and focus on a global optimum rather than many local optima.

3 What are some strategic planning and operational decisions that must be made by an apparel retailer like The Gap?

As The Gap plans supply chain strategy it must first consider the marketing function’s pricing plans in order to structure a supply chain consistent with these plans. Strategic considerations such as the capacity of each supplier and assembly operations, sourcing decisions and how logistics are to be handled are all part of the design. The supply chain must also settle on communication channels and frequencies.

Supply chain planning takes the strategic decisions as a given and seeks to exploit efficiencies in the chain to maximize supply chain surplus. The entire chain should collaborate in forecasting and planning production to achieve a global optimum. The forecasts should take into account planned promotions and known seasonal fluctuations in demand.

The operational decision takes the plans as a given and makes day-to-day decisions to process customer orders, allocate resources to certain customers, trigger orders from supply chain members, and deliver product.

4 Consider the supply chain involved when a customer purchases a book at a bookstore. Identify cycles in this supply chain and the location of the push/pull boundary.

All supply chain processes can be broken down into four process cycles that connect the five stages of the supply chain; the customer order cycle, the replenishment cycle, the manufacturing cycle, and the procurement cycle.

The customer order cycle connects the customer with the retailer; this connection is made as the book, perhaps Supply Chain Management by Chopra and Meindl, is selected and paid for by the customer.

The replenishment cycle connects the retailer and the distributor and is triggered by the retailer’s need to fill the empty shelf space with another copy of this tome.

The manufacturing cycle connects the distributor and the manufacturer. As demand for the book is realized and distributors empty their warehouses, they signal the manufacturer to print another million copies to fill their empty warehouses.

Finally, the procurement cycle connects the manufacturer and the supplier. The manufacturer requires raw material inputs of paper, ink, etc., to begin the assembly process for another batch of Supply Chain Management.

The push/pull boundary exists where demand switches from reactive (pull) to speculative (push) production. For most bookstore supply chains the push/pull boundary is between the customer order cycle and the replenishment cycle. The customer order pulls the book from the book store shelf but the initial production of the book was triggered by a build order that moved materials along the supply chain to the retail outlet.

5 Consider the supply chain involved when a customer orders a book from Amazon. Identify the push/pull boundary and two processes each in the push and pull phases.

In Amazon’s original operations design the push/pull boundary existed betwixt the retailer (Amazon) and their distributor. Amazon ordered product from the distributor and the customer order arrived. Today, Amazon has six warehouses where it stocks an inventory of items it is confident that will sell. In this scenario, the push/pull boundary exists between the customer and the retailer.

Processes in the pull phase are the order fulfillment, shipping, customer returns, and customer billing. Processes in the push phase are production, stock replenishments, shipping, and payment.

6 In what way do supply chain flows affect the success or failure of a firm like Amazon? List two supply chain decisions that have a significant impact on supply chain profitability.

The success or failure of a company like Amazon is decided by the effective function of its supply chain. The flow of products from publishers to distributors to customers must be rapid and reliable in order to satisfy customers. The flow of information back through the supply chain allows all members to coordinate efforts. The flow of money allows all supply chain members to maintain operations. Supply chain profitability is influenced by sourcing, promotion, and fulfillment decisions.

Work Study

2012-09-30T09:37:00.001-07:00

Work Study

Lecture 1

Definition:

Work study may be defined as the analysis of a job for the purpose of finding the preferred method of doing it and also determining the standard time to perform it by the preferred (or given) method. Work study, therefore, comprises of two areas of study: method study (motion study) and time study (work measurement).

Role of Work Study in Improving Productivity

In order to understand the role of work study, we need to understand the role of method study and that of time study.

Method study (also sometimes called Work Method Design) is mostly used to improve the method of doing work. It is equally applicable to new jobs. When applied to existing jobs and existing jobs, method study aims to find better methods of doing the jobs that are economical and safe, require less human effort, and need shorter make-ready / put-away time. The better method involves the optimum use of best materials and appropriate manpower so that work is performed in well organized manner leading to increased resource utilization, better quality and lower costs.

It can therefore be stated that through method study we have a systematic way of developing human resource effectiveness, providing high machine and equipment utilization, and making economical use of materials.

Time study, on the other hand, provides the standard time, that is the time needed by worker to complete a job by the standard method. Standard times for different jobs are necessary for proper estimation of

manpower, machinery and equipment requirements
daily, weekly or monthly requirement of materials
production cost per unit as an input to better make or buy decision
labor budgets
worker's efficiency and make incentive wage payments.

By the application of method study and time study in any organization, we can thus achieve greater output at less cost and of better quality, and hence achieve higher productivity.

Work Study and Ergonomics

The work study and the ergonomics are the two areas of study having the same objective: design the work system so that for the operator it is safe, and the work is less fatiguing and less time taking.

Historical Developments

The Work of Taylor

Frederick W. Taylor is generally considered to be the founder of modern method and time study, although time studies were conducted in Europe many years before Taylor 's time. In 1760, Jean Rodolphe Perronet, a French engineer, made extensive time studies on the manufacture of No. 6 common pins.

Taylor began his time study work in 1881 while associated with the Midvale Steel Company in U.S.A.. He evolved a system based on the “task”, and proposed that the work of each employee be planned out by the management in advance. Each job was to have a standard time, deter mined by time studies made by experts. In the timing process, Taylor advocated dividing the work into small divisions of effort known as "ele ments." Experts were to time these individually and use their collective values to determine the allowed time for the task.

Early presentations of Taylor 's findings were received with little enthusiasm, because many interpreted his findings to be somewhat new piece-rate system rather than a technique for analyzing work and improving methods. Both management and employees were skeptical of piece rates, because many standards were earlier typically based on the supervisor's guess or even sometimes inflated by bosses to protect the performance of their departments.

In June 1903, at the American Society of Mechanical Engineers meeting, Taylor presented his famous paper, "Shop Management," which included the elements of scientific management: time study, standardization of all tools and tasks, use of a planning department, use of slide rule and similar timesaving implements, instruction cards for workers, bonuses for successful per formance, differential rates, mnemonic systems for classifying products, routing systems, and modern cost systems. Taylor 's techniques were well received by many factory managers, and by 1917, of 113 plants that had installed "scientific manage ment," 59 considered their installations completely successful, 20 partly successful, and 34 failures.

In 1898, while at the Bethlehem Steel Company , Taylor carried out the pig-iron experiment that became the most celebrated demonstrations of his principles. He established the correct method, along with financial incentives, and workers carrying 92-pound pigs of iron up a ramp onto a freight car were able to increase their productivity from an average of 12.5 tons per day to between 47 and 48 tons per day. This work was performed with an increase in the daily rate of $1.15 to $1.85. Taylor claimed that workmen per formed at the higher rate "without bringing on a strike among the men, without any quarrel with the men and were happier and better contented."

Another of Taylor 's Bethlehem Steel studies that became famous was on shovel ing work. Workers who shoveled at Bethlehem would use the same shovel for any job—lifting heavy iron ore to lifting light rice coal. Taylor designed shovels to fit the different loads: short- handled shovels for iron ore, long-handled scoops for light rice coal, and showed their usefulness in improving productivity.

Not as well known as his engineering contributions is the fact that in 1881, he was a U.S. tennis doubles champion. Here he used an odd-looking racket he had designed with a spoon curved handle.

The Work of Gilbreths

Frank and Lilian Gilbreth are considered as the founders of the modern motion study technique, which may be defined as the study of the body motions used in performing an oper ation, for the purpose of improving the operation by eliminating unnecessary motions, simplifying necessary motions, and then establishing the most favorable motion sequence for maximum efficiency. Frank Gilbreth originally implemented ideas into the bricklayer's trade in which he was employed. After introducing meth ods improvements through motion study, including an adjustable scaffold that he had invented, as well as operator training, he was able to increase the average num ber of bricks laid from 120 to 350 per worker per hour.

More than anyone else, the Gilbreths were responsible for industry's recogni tion of the importance of a detailed study of body motions to arrive at the best method of performing an operation that would increase production, reduce operator fatigue. They developed the technique of filming motions for study, known as micromotion study.

The Gilbreths also developed the cyclegraphic and chronocyclegraphic analysis techniques for studying the motion paths made by an operator. The cycle- graphic method involves fixing small electric light bulb to the finger or part of the body being studied and then photographing the motion while the operator is performing the operation. The resulting picture gives a permanent record of the motion pattern employed and can be analyzed for possible improvement. The chrono- cyclegraph is similar to the cyclegraph, but its electric circuit is interrupted regularly, causing the light to flash. Instead of showing solid lines of the motion patterns, the resulting photograph shows short dashes of light spaced in proportion to the speed of the body motion being photographed. Consequently, with the chronocyclegraph it is possible to determine direction and compute velocity, acceleration, and deceleration, in addition to study of body motions.

The Work of Others

Carl G. Barth, an associate of Frederick W. Taylor, developed a production slide rule for estimating the most efficient combinations of speeds and feeds for cutting metals of various hardnesses, considering the depth of cut, size of tool, and life of the tool. He is also known for his work on estimation of allowances by establishing the number of foot-pounds of work a worker could do in a day. He developed a relationship in which a certain push or pull on a worker's arms was equated with the amount or weight that worker could handle for a certain percentage of the day.

Harrington Emerson applied scientific methods to work on the Santa Fe Railroad and wrote a book, Twelve Principles of Efficiency, in which he made an attempt to lay down procedures for efficient operation. He reorganized the company, integrated its shop procedures, installed standard costs and a bonus plan, and introduced Hollerith tabulating machines for the accounting work. This effort resulted in annual saving of $ 1.5 million and recognition of his approach, called efficiency engineering .

In 1917, Henry Laurence Gantt developed simple graph that would present performance while visually showing projected schedules. This production control tool was adopted by the shipbuilding industry during World War I. For the first time, this tool demonstrated the possibility of comparing actual performance against the original plan, and to adjust daily schedules in accordance with capacity, back log, and customer requirements. Gantt is also known for his wage payment system that rewarded workers for above-standard performance, eliminated any penalty for failure, and offered the boss a bonus for every worker who per formed above .standard. Gantt advocated human relations and promoted scientific management in the back drop of an inhuman "speedup" of labor.

Motion and time study received added stimulus during World War II when Franklin D. Roosevelt, through the U.S. Department of Labor, attempted to establish standards for increasing production. The stated policy advocated greater pay for greater output but without an increase in unit labor costs, incentive schemes to be collectively bargained between labor and management, and the use of time study for setting production standards.

Lecture 2

Method Study

Method study, aims to achieve the better method of doing work, and for this reason method study is sometimes called Work Method Design.

Definition: Method study can be defined as the procedure for systematic recording, analysis and critical examination of existing or proposed method of doing work for the purpose of development and application of easier and more effective method.

Method Study Procedure

The following general steps describe the procedure for making a method study.

Select the job – on which method study is to be applied.
Obtain information and record.
Examine the information critically.
Develop the most practical, economical and effective method by considering real limitations of the situation.
Install the new method as standard practice.
Maintain the standard practice by regular follow up.

Let us consider these steps in some detail.

Selection of Job for Method Study

Practically, any activity or a job is a potential project for improvement but as the work study engineer is to sell his ideas and maintain his existence in the organisation, he should always attempt to select those jobs for improvement which are unpopular among employees or are considered “dirty” by them.

By improving such jobs, he would earn goodwill from the employees as well as the management, and can expect their full cooperation for other studies in the future.

Considerations may be given to the following factors while selecting a job for method study

• Economic Factors

• Technical Factors

• Human Factors

Economic Factors:

If the economic importance of a job is small, it is not wise to start or continue a long study. Priorities should be given to those types of job which offer greater potential for cost reduction. Such jobs are easily identifiable, as they have

• High labour content, i.e. they consume more time

• excessive machine or man idleness

• higher frequency of occurrence, i.e. they have large demand

• bottlenecks in production line

• higher proportion of accidents

• movement of material or men over long distance

• high scrap and reprocessing costs

• high payment of overtime bills.

Technical Factors: The method study engineer must have the necessary technical knowledge about the job to be studied. Only surface knowledge about the subject may not lead to the right solution to the real problem. To illustrate, consider that a particular machine tool in proving bottleneck. The output from this machine is not reaching the assembly line in the required quantity. Through a preliminary study, it is found that it is running at lower speed and feed than that recommended for the pair of work and tool material used. Just increase in speed or feed may not be the solution of this problem. It may be possible that the machine itself is not rigid enough to operate at higher speeds or take a deeper cut. Just increase in speed may increase the output but the quality of job may be seriously affected. Technical expertise in machine tools and metal cutting process would be essential to solve problem of this kind.

Human Factors: Emotional reaction of the workers to the method study and changes in method are important considerations. If the study of a particular job is suspected to cause unrest or ill feeling, it should not be undertaken, however useful it may be from the economic point of view. It is always better to take up first those jobs which are considered ‘dirty', unsafe, unpleasant, boring, or highly fatiguing, and improvements brought about as a result of method study. This would possibly ensure cooperative from the workers for the other jobs as well.

After it is recognized that a problem exists, the first step is to properly formulate it. From the general statements like “Costs are too high“, “Increase the production”, “Reduce shop floor accidents”, it is necessary to determine just what the real problem is. After it is ascertained that the problem merits consideration, it is decided whether this is the proper time to solve it, and how much time can be spent in solving it. The problem may then be defined broadly giving minimum constraints at this stage, as it will permit the use of imagination and creativity in finding a solution. It may sometimes be desirable to divide the complete problem into a couple of small problems and solve them.

Lecture 3

Information Collection and Recording

Information Collection Techniques:

The accuracy of data about the method study problem is important for the development of improved method. The following techniques are used for the collection of information / data about the task under consideration. These are not exclusive of each other, and for any particular method study problem, some or all the techniques may be employed.

• Observation. It is a common technique used for collecting information about the present method or the existing problem. The method study person visits the site where the work is currently being done and observes various steps in the method being followed. There are many instances where all the data needed is obtained by only observing the work or work site.

• Discussion. Discussion with those who do or who supervise the work can frequently provide information not obtainable by observation. The discussion technique is commonly used where irregular work is involved or where one is trying to analyze past work in order to improve efficiency of work to be done in future.

Even where observation by itself may accomplish the data collection task, discussion may be used for developing good human relations.

• Records. Valuable information can be obtained from past records concerning production, cost, time, inventory and sub-contracts. For certain type of information concerning the past practice, sometimes this is the only way to obtain authentic data.

• Motion Pictures or video Films. Accurate and most detailed information can be obtained by taking motion pictures or video film. Information obtained by this procedure can easily be transmitted / forwarded to all levels in the organization and if needed, can be used directly for training purposes. The film can be used to focus attention at particular point or motion in an operation. For obtaining information concerning those types of work that involve large crew size, it is probably the only procedure.

Information Recording Techniques:

There are three main types of information recording techniques. These are

• Process Charts

• Diagrams

• Templates

A Process Chart is a graphic means of representing the activities that occur during a manufacturing or servicing job.

There are several types of process charts. These can be divided into two groups.

(i) Those which are used to record a process sequence (i.e. series of events in the order in which they occur) but do not depict the events to time scale.

Charts falling in this group are

• Operation process chart

• Flow process chart – (man / material / equipment type)

• Operator chart (also called Two Handed Process Chart)

(ii) Those which record events in the sequence in which they occur on a time scale so that the interaction of related events can be more easily studied. Charts falling in this group are

• Multiple activity chart

• Simo chart

Diagrams. A diagram gives pictorial view of the layout of workplace or floor on which locations of different equipment, machines, etc. are indicated. The movement of subject (man or material) is then indicated on the diagram by a line or a string. The diagrams are valuable in highlighting the movement so that analyst can take steps to simplify or reduce it and thus effect saving in time or reduction in collisions / accidents.

Two types of diagrams are common: Flow diagram and string diagram.

Templates and 3-D models:

Two-dimensional cut outs made from thin card sheet representing machinery, furniture, etc. can be used for developing new layouts and methods. The templates may have pieces of permanent magnet attached to them, so that when used on iron board; they remain glued on the board whenever placed.

A scaled 3-D model of a working area helps easy understanding of lighting, ventilation, maintenance and safety aspects that may be important in a method. Such models are often of great value in demonstrating the advantages of the proposed changes to all concerned. However, their use is limited because of higher cost involved. Some computer softwares are available which help in constructing the layout and possibility of visualizing the working of process in a systematic way.

Before taking up descriptions of these charts or diagrams, it is necessary to know the various elements of work.

Elements of Work:

There are five basic elements of work: Operation, Inspection, Transportation, Delay, and storage. Table gives the definitions and symbols by which these elements are represented. Also given in the Table are examples of each element.

Sometimes, more than one element occur simultaneously. It is shown as combined element with combined symbol. Examples are “Operation in combination will inspection”, and “Inspection in combination with Transportation”.

Operation Process Chart:

An operation process chart provides the chronological sequence of all operations and inspections that occur in a manufacturing or business process. It also shows materials used and the time taken by operator for different elements of work. Generally a process chart is made for full assembly, that is, it shows all the operations and inspections that occur from the arrival of raw material to the packaging of the finished product.

Flow Process Chart:

A flow process chart is used for recording greater detail than is possible in an operation process chart. It is made for each component of an assembly rather than for the whole assembly.

A flow process chart shows a complete process in terms of all the elements of work. There are two main types of flow charts: product or material type , and the operator type . The product type records the details of the events that occur to a product or material, while the operator flow chart details how a person performs an operational sequence.

An important and valuable feature of this chart is its recording of non-productive hidden costs, such as delays, temporary storages, unnecessary inspections, and unnecessary long distances traveled. When the time spent on these non productive activities is highlighted, analyst can take steps to minimize it and thus reduce costs.

Operator Process Chart :

It is also called Left Hand – Right Hand chart and shows the activities of hands of the operator while performing a task. It uses four elements of hand work: Operation, Delay (Wait), Move and Hold. Its main advantage lies in highlighting un-productive elements such as unnecessary delay and hold so that analyst can take measures to eliminate or shorten them.

Multiple Activity Chart:

Worker-Machine process chart and gang process chart fall in the category of multiple activity charts. A worker-machine chart is used for recording and analyzing the working relationship between operator and machine on which he works. It is drawn to time scale. Analysis of the chart can help in better utilization of both worker and machine time. The possibility of one worker attending more than one machine is also sought from the use of this chart.

A gang process chart is similar to worker-machine chart, and is used when several workers operate one machine. The chart helps in exploring the possibility of reducing both the operator time and idle machine time.

Simo Chart:

A Simo chart is another Left-Hand Right-Hand chart with the difference that it is drawn to time scale and in terms of basic motions called therbligs. It is used when the work cycle is highly repetitive and of very short duration.

Lecture 4

CRITICAL EXAMINATION

Critical examination of the information recorded about the process in charts / diagrams is the most important phase of the method study. In this, each element of the work, as presently being done and recorded on the chart is subjected to a systematic and progressive series of questions with the purpose of determining true reasons for which it is done. Based on the reasons, improvements are found and adopted into a new method, called better method. This examination, thus requires exhaustive collaboration with everyone whose contribution can prove useful, and also full use of all available sources of technical information. The use of questioning technique reduces the possibility of missing any information which may be useful for the development of better method.

A popular procedure of carrying out critical examination uses two sets of questions: Primary questions (answers to these show up the necessity of carrying out the activity), and Secondary questions (answers to these allow considerations to alternative methods of doing the activity). Selection of the best way of doing each activity is later determined to develop new method which is introduced as a standard practice.

A general-purpose set of primary and secondary questions is given below:

Primary Questions:

1. Purpose. The need of carrying out the activity is challenged by the questions-What is achieved? Is it necessary? Why?

The answers to these questions determine whether the particular activity will be included in the proposals of new method for the process.

2. Means. The means of carrying out the activity are challenged by the questions- 'How is it done?' and 'Why that way'?

3. Place. The location of carrying out the activity is challenged by the questions- 'Where is it done'? and 'Why there'?

4. Sequence. The time of carrying out the activity is challenged by the questions- 'When is it done'? and 'Why then'?

5. Person. The level of skill and experience of the person performing the activity is challenged by the questions- 'Who does it'? and 'Why that person'?

The main object of the primary questions is to make sure that the reasons for every aspect of the presently used method are clearly understood. The answers to these questions should clearly bring out any part of the work which is unnecessary or inefficient in respect of means, sequence, person or place.

Secondary Questions:

The aim of secondary questions is to arrive at suitable alternatives to the presently used method:

1. Purpose. If the answer to the primary question 'Is the activity necessary"? is convincingly 'Yes', alternatives to achieve the object of carrying nut the activity are considered by the question— 'What else could be done'?

2. Means. All the alternative means to achieve the object are considered by the question— 'How else could it be done'?

3. Place. Other places for carry ing out the activity are considered by the question— 'Where else could it be done'?

4. Sequence. The secondary question asked under this heading is— 'When else could it be clone'?

5. Person. The possibilities for carrying out the activity by other persons are considered by asking the question- 'Who else should do it' ?

This phase involves the search of alternative possibilities within the imposed restrictions of cost, volume of production, and the like. For this the method study man uses his own past experience with same or similar problems or refers to text books, handbooks, etc.

The answers to the following questions are then sought through evaluation of the alternatives.

'What should be done'?

'How should it be done'?

'Where should it be done'?

'When should it be done'? and

'Who should do it'?

These answers form the basis of the proposals for the improved method. The evaluation phase requires the work study man to consider all the possibilities with respect to the four factors—economic, safety, work quality and human factors—the economic factor being the most important in most situations.

Economic considerations to any alternative refer to determination of 'How much will it cost'? and 'How much will it save'? The purpose of evaluating safety factor is to ensure that the alternative selected shall not make the work less safe. The evaluation of quality factor shall determine whether the alternative selected shall make for better product quality or quality control.

And lastly human factors considerations shall ensure that the new method will be interesting, easy to learn, safe, less monotonous and less fatiguing to the operator.

Figure shows a sample sheet used for critical examination the use of which can be quite helpful in this phase of method study.

Lecture 5

Developing Better Method:

With the present method or procedure for the job in mind, the application of ‘critical analysis' highlights the essential part of the job, for which alternative ways for its carrying out are developed .

When developing alternative ways for doing a task the following may be considered.

• Where and how to use ‘man' in the process?

• What better work procedure be adopted?

• What better equipment be used?

• What better layout of work station, shop or factory be used?

In deciding whether a particular element of work (operation, inspection, or transportation) be carried out manually or with the help of a device, method study engineer must be well aware of things which man cannot do or does in inferior fashion than machine. Examples of such things are:

Exert large amount of force, as needed in metal cutting.
Exert force precisely or smoothly at a fixed rate as needed in metal forming.
Do high speed computations of complex nature.
Perform repetitive tasks without suffering from side effects like boredom, fatigue, etc.
Move at high speeds for hours together.
Carry out several tasks simultaneously.
Respond fast to frequently changing control signals.
Perform satisfactorily in an environment where conditions relating to cold, heat, noise, dampness, etc. are extreme.

In contrast, machines prove inferior generally when for carrying out a task it is necessary to

a. Think creatively or inductively

b. Learn

c. Generalize

d. Cope will unexpected events.

In most cases, the relative roles of man and machine vary from one extreme end in which entire process is manual to the other extreme in which the process is completely mechanized with the presence of man only for monitoring, trouble shooting, maintenance, and the like.

Man is readily available and extremely flexible tool, who has the capability of doing a large number and type of tasks with learning and practice that is generally less expensive than the cost of creating devices for the same purpose. Man is therefore considered a strong competitor for low, medium and even some high volume production tasks.

When an activity is decided to be carried out manually, the best work procedure is determined by considering the principles of Motion Economy.

Equipped will the various alternative ways of carrying out essential elements of task, method study engineer has now to choose the best alternative method. He decides upon the criteria, which may be additional fixed costs involved, running cost, production rate, operator's fatigue, operator learning time, and the like. The weight to each criterion is fixed and performance is predicted of each alternative with respect to each criteria. The one which gets the maximum points is selected for adoption as a standard method.

Detailed specifications of this method are prepared with the description of procedure, workplace layout and material/equipment to be used. This is important for

• Communication of the proposed work method to those responsible for its approval

• Communication of the proposed method to those concerned with its installation, for example instructors and supervisors who are actually responsible for instructions to operators and setting up the machinery and work place layouts.

• Official record of the work method.

Installation of Improved Method:

When the proposals of the improved method for a job are approved by the management of the company, the next step is to put this method into practice. Installation of method requires necessary prior preparation for which the active support of everyone concerned is very important.

The activities of the installation phase include:

1. Gaining acceptance of the change by the workers involved and their representatives. The method change may affect the routine and paper work of wages, costs, planning, and even purchase department. It may require displacement of staff from one section to another of the organisation. Adjustments of this type need to be carried out very carefully so that the least possible hardship or inconvenience is caused.

2. Retraining the workers. The extent to which workers need retraining will depend on the nature of the job and the changes involved. It is much more for those jobs which have a high degree of manual dexterity and where the workers have been doing the work by traditional methods. The use of films demonstrating the advantages of new method as compared to traditional one are often very useful in retraining the workers.

3. Arranging the requirements of the new method. This involves -

(i) arranging the necessary plant, tools and equipment at all the workplaces,

(ii) arranging building-up of necessary stocks of new raw materials, and running-down of old stocks,

(iii) checking up the availability and continuity of all supplies and services, and

(iv) arranging any clerical records which may be required for purposes of control and comparison.

4. Taking other necessary actions. These will depend upon situation to situation. For example, if changes in working hours are involved, necessary instructions should be passed on to auxiliary services such as transport, canteen, water supply, etc. If change in wages is involved, information concerning the date of installation must reach the costing department. Necessary instructions should be passed on to every one concerned about the time table for the installation of the change in method.

5. Giving a trial run to the new method. It is important that all departments affected by the change are represented at the rehearsal. It is often advantageous to conduct the rehearsal while the old method is still operating. It should usually take place outside normal working hours; say at week-end or at holiday time so that there is no interference with normal production. The suggestions for minor variations in the proposed method if they are worth while and cost effective should be accepted and incorporated.

It is obvious that the method analyst has to be extra tactful and keep restraint throughout the period of installation. The installation is considered complete when the new method starts running smoothly.

Follow-up:

The work of method study man is not complete with the installation of the improved method; the maintenance of the new method in its specified form is also part of his activities. The main aim of maintenance of the new method is to ensure that the workers do not slip back into old method, or introduce elements which are not part of the proposed method.

For effective maintenance it is important to define and specify the new method very clearly. An operator chart giving adequate details of the tools, equipment, and workplace layout and operator-motion pattern is often helpful.

The workers have tendencey to drift away from the method laid down. The purpose of the method-maintenance is to check this tendency. But if it is found that the change from the method specified is in fact an improvement which can be made in the method, this should be officially incorporated.

Lecture 6

Motion Study

Motion study is a technique of analyzing the body motions employed in doing a task in order to eliminate or reduce ineffective movements and facilitates effective movements. By using motion study and the principles of motion economy the task is redesigned to be more effective and less time consuming.

The Gilbreths pioneered the study of manual motions and developed basic laws of motion economy that are still relevant today. They were also responsible for the development of detailed motion picture studies, termed as Micro Motion Studies, which are extremely useful for analyzing highly repetitive manual operations. With the improvement in technology, of course, video camera has replaced the traditional motion picture film camera.

In a broad sense, motion study encompasses micro motion study and both have the same objective: job simplification so that it is less fatiguing and less time consuming. While motion study involves a simple visual analysis, micro motion study uses more expensive equipment. The two types of studies may be compared to viewing a task under a magnifying glass versus viewing the same under a microscope. The added detail revealed by the microscope may be needed in exceptional cases when even a minute improvement in motions matters, i.e. on extremely short repetitive tasks.

Taking the cine films @ 16 to 20 frames per second with motion picture camera, developing the film and analyzing the film for micro motion study had always been considered a costly affair. To save on the cost of developing the film and the cost of film itself, a technique was used in which camera took only 5 to 10 frames per minute. This saved on the time of film analysis too. In applications where infrequent shots of camera could provide almost same information, the technique proved fruitful and acquired the name Memo Motion Study.

Traditionally, the data from micro motion studies are recorded on a Simultaneous Motion (simo) Chart while that from motion studies are recorded on a Right Hand - Left Hand Process Chart.

Therbligs

On analysing the result of several motion studies conducted, Gilbreths concluded that any work can be done by using a combination of some or all of 17 basic motions, called Therbligs (Gilbreth spelled backward). These can be classified as effective therbligs and ineffective therbligs. Effective therbligs take the work progress towards completion. Attempts can be made to shorten them but they cannot be eliminated. Ineffective therbligs do not advance the progress of work and therefore attempts should be made to eliminate them by applying the Principles of Motion Economy. Table gives different therbligs along with their symbols and descriptions.

SIMO Chart

It is a graphic representation of an activity and shows the sequence of the therbligs or group of therbligs performed by body members of operator. It is drawn on a common time scale. In other words, it is a two-hand process chart drawn in terms of therbligs and with a time scale, see Figure.

Making the Simo Chart. A video film or a motion picture film is shot of the operation as it is carried out by the operator. The film is analyzed frame by frame. For the left hand, the sequence of therbligs (or group of therbligs) with their time values are recorded on the column corresponding to the left hand. The symbols are added against the length of column representing the duration of the group of therbligs. The procedure is repeated for the right hand and other body members (if any) involved in carrying out the operation.

It is generally not possible to time individual therbligs. A certain number of therbligs may be grouped into an element large enough to be measured as can be seen in Figure.

Uses of Simo Chart

From the analysis shown about the motions of the two hands (or other body members) involved in doing an operation, inefficient motion pattern can be identified and any violation of the principle of motion economy can be easily noticed. The chart, therefore, helps in improving the method of doing an operation so that balanced two-handed actions with coordinated foot and eye motions can be achieved and ineffective motions can be either reduced or eliminated. The result is a smoother, more rhythmic work cycle that keeps both delays and operator fatigue to the minimum extent.

Lecture 7

Cycle graph and Chrono cycle graph

These are the techniques of analyzing the paths of motion made by an operator and were originally developed by the Gilbreths. To make a cycle graph , a small electric bulb is attached to the finger, hand, or any other part of the body whose motion is to be recorded. By using still photography, the path of light of bulb (in other words, that of the body member) as it moves through space for one complete cycle is photographed. The working area is kept relatively less illuminated while photograph is being taken. More than one camera may be used in different planes to get more details. After the film is developed, the resulting picture (cycle graph) shows a permanent record of the motion pattern employed in the form of a closed loop of white continuous line with the working area in the background. A cycle graph does not indicate the direction or speed of motion.

It can be used for

Improving the motion pattern, and
Training purposes in that two cycle graphs may be shown with one indicating a better motion pattern than the other.

The chrono cycle graph is similar to the cycle graph, but the power supply to the bulb is interrupted regularly by using an electric circuit. The bulb is thus made to flash. The procedure for taking photograph remains the same. The resulting picture (chrono cycle graph), instead of showing continuous line of motion pattern, shows short dashes of line spaced in proportion to the speed of the body member photographed. Wide spacing would represent fast moves while close spacing would represent slow moves. The jumbling of dots at one point would indicate fumbling or hesitation of the body member. A chrono cycle graph can thus be used to study the motion pattern as well as to compute velocity, acceleration and retardation experienced by the body member at different locations. Figures show a cycle graph and a chrono cycle graph.

The world of sports has extensively used this analysis tool, updated to video, for the purpose of training in the development of form and skill.

Principles of Motion Economy:

These principles can be considered under three different groups.

• Those related to the use of the human body.

• Those related to the workplace arrangement, and

• Those related to the design of tools and equipment.

1. Principles related to the use of human body:

(i) Both hands should begin and end their basic divisions of activity simultaneously and should not be idle at the same instant, except during the rest periods.

(ii) The hand motions should be made symmetrically and simultaneously away from and toward the centre of the body.

• Momentum should be employed to assist the worker wherever possible, and it should be reduced to a minimum if it must be overcome by muscular effort.

• Continuous curved motions should be preferred to straight line motions involving sudden and sharp changes in the direction.

• The least number of basic divisions should be employed and these should be confined to the lowest practicable classifications. These classifications, summarized in ascending order of time and fatigue expended in their performance, are:

• Finger motions

• Finger and wrist motions.

• Finger, wrist, and lower arm motions.

• Finger, wrist, lower arm, and upper arm motions.

• Finger, wrist, lower arm, upper arm motions and body motions.

• Work that can be done by the feet should be arranged so that it is done together with work being done by the hands. It should be recognized, however, that it is difficult to move the hand and foot simultaneously.

• The middle finger and the thumb should be used for handling heavy loads over extended periods as these are the strongest working fingers. The index finger, fourth finger, and little finger are capable of handling only light loads for short durations.

• The feet should not be employed for operating pedals when the operator is in standing position.

• Twisting motions should be performed with the elbows bent.

• To grip tools, the segment of the fingers closed to the palm of the hand should be used.

2. Principles related to the arrangement and conditions of workplace:

• Fixed locations should be provided for all tools and materials so as to permit the best sequence and eliminate search and select .

• Gravity bins and drop delivery should be used to reduce reach and move times. Use may be made of ejectors for removing finished parts.

• All materials and tools should be located within the normal working area in both the vertical and horizontal plane ( see Figure ), and as close to the point of use as possible.

• Work table height should permit work by the operator in alternately sitting and standing posture.

• Glare-free adequate illumination, proper ventilation and proper temperature should be provided.

• Dials and other indicators should be patterned such that maximum information can be obtained in minimum of time and error.

3. Principles related to the design of tools and equipment:

• Use colour, shape or size coding to maximize speed and minimize error in finding controls.

• Use simple on/off, either/or indicators whenever possible. If simple on/off indicator is not sufficient, use qualitative type indicator, and use quantitative type indicator only when absolutely essential.

• All levers, handles, wheels and other control devices should be readily accessible to the operator and should be designed so as to give the best possible mechanical advantage and utilize the strongest available muscle group. Their direction of motion should conform to stereo-typed reactions.

• Use quick acting fixture to hold the part or material upon which the work is being performed.

• Use stop guides to reduce the control necessary in positioning motions.

• Operating, set-up and emergency controls should be grouped according to the function.

Design of Workplace Layout

The design of workplace layout involves the following

Determination of work surface height
Design of operator chair (if work is to be done in sitting posture), or allowing the use of antifatigue mats for standing operator
Determination of location of tools, materials, controls, displays and other devices.

We shall consider these briefly.

Work Place Height

This should be decided from the standpoint of comfortable working posture for the operator. Generally, it is equal to the elbow height of operator whether work is done in standing or sitting posture. However, for work involving lifting of heavy parts, it is useful to lower the work surface height by as much as 20 cm. This would reduce the fatigue to the trunk of operator. Similarly, it may be useful to raise the work surface height when work involves visual examination of minute details of fine parts. This would reduce the eye fatigue to the operator. Alternatively, the work surface may be inclined by 15 degrees or so. Work surface height may also be made adjustable in situations where operator is permitted to do work in alternatively sitting and standing postures.

Design of Operator Chair

A seated posture is better than standing posture from the standpoint of stress reduction on the feet and the overall energy expenditure. A well-designed seat should

Provide trunk stabilization so that a good posture is maintained,
Permit change of posture, and
Not unduly press the thigh tissues.

This requires the use of ergonomic considerations and anthropometric dimensions of operator so that appropriate dimensions are chosen for the following features of chair

(i) Seat Height

(ii) Seat Depth

(iii) Seat Width

(iv) Seat Inclination

(v) Arm Rests

(vi) Back Rest

(vii) Foot Rest

It is necessary to provide adjustability, particularly with respect to seat height, in order that the same seat (or chair) is useable by many operators doing same job.

Standing for long periods of time on a cemented floor is fatiguing. If operator has to work only in standing posture, it is essential to provide resilient anti-fatigue floor mats. Such mats allow small muscle contractions in the legs and force the blood to keep circulating.

Determination of location of tools, materials, controls, displays and other devices.

We all know that greater the distance through which operator moves his body member while doing work, larger is the requirement of muscular effort, control and time. This means that all tools, materials, controls, etc need to be located within close reach of the operator. In this context, two areas can be identified: normal working area and maximum working area. Figure identifies these areas in horizontal and vertical planes.

Within these areas, all tools, materials, controls, displays and other devices must be located on the basis of any of the following principles.

(i) Importance Principle. According to this principle, the most important item or group of items is first located within the normal area in the best position. The next important component item or group of items is then selected and located in the best location within the remaining area. In this way, all the items are located.

(ii) Frequency of Use Principle. According to this principle, the item with the greatest frequency of use has the highest priority for location at the optimum position. From within the remaining items to be located in the remaining area, the same principle can then be applied repetitively.

(iii) Functional Principle. This principle provides for grouping of items according to their function. For instance, all controls that are functionally related may be grouped together and located at one place.

(iv) Sequence of Use Principle. According to this principle, items are located according to sequence of their use. For illustration, let us consider the case of assembly. As we know, an assembly is made by assembling the sub-assemblies in a specific order. From motion economy or production efficiency point of view, it would be better if sub-assemblies and other items are located in the sequence in which they are to be used in assembly.

Further, for better productivity, it is important that location of all tools, materials and controls be fixed so that their "search" and “select" is minimized.

Lecture 8

Work Measurement

Work measurement refers to the estimation of standard time for an activity, that is the time allowed for completing one piece of job by using the prescribed method. Standard time can be defined as the time taken by an average experienced worker for the job with provisions for delays beyond the worker's control.

There are several techniques used for estimation of standard time in industry. These include time study, work sampling, standard data, and predetermined motion time system.

Applications:

Standard times for operations are useful for several applications in industry, like

• Estimating material, machinery, and equipment requirements.

• Estimating production cost per unit as an input to

Preparation of budgets
Determination of selling price
Make or buy decision

• Estimating manpower requirements.

• Estimating delivery schedules and planning the work

• Balancing the work of operators working in a group.

• Estimating performance of workers and using that as the basis for incentive payment to those direct and indirector labor who show greater productivity.

We will study some of the popular techniques of work measurement.

TIME STUDY. It is the most versatile and the most widely used technique of work measurement.

Definition:

Time study is a technique to estimate the time to be allowed to a qualified and well-trained worker working at a normal pace to complete a specified task by using specified method.

This technique is based on measuring the work content of the task when performed by the prescribed method, with the allowance for fatigue and for personal and unavoidable delays.

Time Study Procedure:

The procedure for time study can best be described step-wise, which are self explanatory.

Step 1: Define objective of the study. This involves statement of the use of the result, the precision desired, and the required level of confidence in the estimated time standards.

Step 2: Verify that the standard method and conditions exist for the operation and the operator is properly trained. If need is felt for method study or further training of operator, the same may be completed before starting the time study.

Step 3: Select operator to be studied if there are more than one operator doing the same task.

Step 4: Record information about the standard method, operation, operator, product, equipment, and conditions on the Time Study observation sheet.

Step 5: Divide the operation into reasonably small elements, and record them on the Time Study observation sheet.

Step 6: Time the operator for each of the elements. Record the data for a few number of cycles on the Time Study observation sheet. Use the data to estimate the total number of observations to be taken.

Step 7: Collect and record the data of required number of cycles by timing and rating the operator.

Step 8: Calculate the representative watch time for each element of operation. Multiply it by the rating factor to get normal time.

Normal time = Observed time x Rating factor

Calculate the normal time for the whole operation by adding the normal time of its various elements.

Step 9: Determine allowances for fatigue and various delays.

Step 10: Determine standard time of operation.

Standard time = Normal time + allowances

Selection of job for Time Study

Time Study is conducted on a job

• which has not been previously time-studied.

• for which method change has taken place recently.

• for which worker(s) might have complained as having tight time standards.

Selection of Worker for Time Study

The selection of worker for time study is a very important factor in the success of the study. If there is only one person on the job, as usually is, then there is no choice. But if more than one person is performing the same operation, the time study man may time one or more of the workers. If all the workers are using the same method for doing the job and there is different in the rate of their doing it, it is necessary to select a suitable worker for the study. The worker on which time study should be conducted must

have necessary skill for the job.
have sufficient experience with the given method on the job (that is, he should have crossed the learning stage).
be an ‘average' worker as regards the speed of working.
be temperamentally suited to the study (those who can't work in normal fashion when watched, are not suitable for the study).
have knowledge about the purpose of study.

Time Study Equipment

The following equipment is needed for time study work.

• Timing device

• Time study observation sheet

• Time study observation board

• Other equipment

Timing Device. The stop watch ( see Figure ) is the most widely used timing device used for time study, although electronic timer is also sometimes used. The two perform the same function with the difference that electronic timer can measure time to the second or third decimal of a second and can keep a large volume of time data in memory.

Time Study Observation Sheet. It is a printed form with spaces provided for noting down the necessary information about the operation being studied, like name of operation, drawing number, and name of the worker, name of time study person, and the date and place of study. Spaces are provided in the form for writing detailed description of the process (element-wise), recorded time or stop-watch readings for each element of the process, performance rating(s) of operator, and computation. Figure shows a typical time study observation sheet.

Time Study Board. It is a light -weight board used for holding the observation sheet and stopwatch in position. It is of size slightly larger than that of observation sheet used. Generally, the watch is mounted at the center of the top edge or as shown in Figure near the upper right-hand corner of the board. The board has a clamp to hold the observation sheet. During the time study, the board is held against the body and the upper left arm by the time study person in such a way that the watch could be operated by the thumb/index finger of the left hand. Watch readings are recorded on the observation sheet by the right hand.

Other Equipment. This includes pencil, eraser, device like tachometer for checking the speed, etc.

Dividing Work into Short Elements

Timing a complete task as one element is generally not satisfactory. For the purpose of time study the task is normally broken
into short elements and each element is timed separately, for the following
reasons:

(1) To separate unproductive part of task from the productive one.

(2) To improve accuracy in rating. The worker may not work at the
same speed throughout the cycle. He may perform some elements faster and
some slower. Breaking of task into short elements permits rating of each
element separately which is more realistic than just rating once for the complete
cycle.

(3) To identify elements causing high fatigue. Breaking of task into short elements permits giving appropriate rest allowances to different elements.

(4) To have detailed job specifications. This helps in detection of any variation in the method that may occur after the time standard is established.

(5) To prepare standard data for repeatedly occurring elements.

The following guidelines should be kept in mind while dividing a task into elements.

(1) The elements should be of as short duration as can be accurately timed. (This in turn, depends on the skill of the time study man, method of timing and recording, and many other factors. Generally, with the stop watch, elements of duration less than 0.03 to 0.05 minute are difficult to time accurately. The elements should not normally be longer than 0.40 min.).

(2) Manually performed elements should be separated from machine paced elements. (Time for machine paced elements can be determined by calculation). Machine elements are not rated against a normal. This rule also helps in recognition of delays.

(3) Constant elements should be separated from variable elements.
(Constant elements are those elements which are independent of the size, weight,
length, or shape of the workpiece. For example, the time to pick screw driver
from its place and bring it to the head of a screw is constant, whereas the time
to tighten or loosen the screw is a variable, depending upon the length and
size of the screw).

(4) The beginnings and endings of elements should be easily distinguishable. These should preferably be associated with some kind of sound.

(5) Irregular elements, those not repeated in every cycle, should be separated from regular elements. For example, if the jig is cleaned off after every ten parts produced, "cleaning" is an irregular element, and its time should be spread over ten cycles.

(6) Unnecessary motions and activities should be separated from those considered essential.

(7) Foreign or accidental elements should be listed separately. Such elements are generally of non-repetitive type.

Number of cycles to be timed.

The following general principles govern the number of cycles to get the representative average cycle time.

(1) Greater the accuracy desired in the results, larger should be the number of cycles observed.

(2) The study should be continued through sufficient number of cycles so that occasional elements such as setting-up machine, cleaning of machine or sharpening of tool are observed for a good number of times.

(3) Where more than one operator is doing the same job, short study (say 10 to 15 cycles) should be conducted on each of the several operators than one long study on a single operator.

It is important that enough cycles are timed so that reliable average is obtained.

Following techniques are used to determine the number of cycles to be timed.

(i) Use of Tables: On the consideration of the cost of obtaining the data and the desired accuracy in results, most companies have prepared their own tables for the use of time study people, which indicate the number of cycles to be timed as a function of the cycle time and the frequency of occurrence of the job in the company. For example, one Company uses the Table for such purposes.

(ii) Statistical methods: On the basis of the requirements of the particular situation involved, accuracy and confidence level are decided (An accuracy of a confidence level of 95% is considered reasonable in most cases). A preliminary study is conducted in which some (say N) cycles are timed. Standard deviation o of these (N) observations is calculated as

(iii) Mundel Method: In this method the following steps are followed.

Step 1. Take a few good watch readings of the work cycle. (Generally, 10 readings are taken if cycle time is less than 2 minutes, otherwise 5 readings).

Step 2. Find the ratio , where H and L are respectively the highest and the lowest value of the leading.

Step 3. Corresponding to the value of the ratio, determine the number of observations from the Table

Normal Performance

There is no universal concept of Normal Performance. However, it is generally defined as the working rate of an average qualified worker working under capable supervision but not under any incentive wage payment scheme. This rate of working is characterized by the fairly steady exertion of reasonable effort, and can be maintained day after day without undue physical or mental fatigue.

The level of normal performance differs considerably from one company to another. What company a calls 100 percent performance, company B may call 80 percent, and company C may call 125 percent and so on. It is important to understand that the level that a company selects for normal performance is not critical but maintaining that level uniform among time study persons and constant with the passage of time within the company is extremely important.

There are, of course, some universally accepted benchmark examples of normal performance, like dealing 52 cards in four piles in 0.5 minute, and walking at 3 miles per hour (4.83 km/hr). In order to make use of these benchmarks, it is important that a complete description about these be fully understood, like in the case of card dealing, what is the distance of each pile with respect to the dealer, technique of grasping, moving and disposal of the cards.

Some companies make use of video films or motion pictures for establishing what they consider as normal speed or normal rate of movement of body members. Such films are made of typical factory jobs with the operator working at the desired normal pace. These films are found to be useful in demonstrating the level of performance expected from the operators and also for training of time study staff.

Lecture 9

Performance Rating

During the time study, time study engineer carefully observes the performance of the operator. This performance seldom conforms to the exact definition of normal or standard. Therefore, it becomes necessary to apply some 'adjustment' to the mean observed time to arrive at the time that the normal operator would have taken to do that job when working at an average pace. This 'adjustment' is called Performance Rating.

Determination of performance rating is an important step in the work measurement procedure. It is based entirely on the experience, training, and judgment of the work-study engineer. It is the step most subjective and therefore is subject to criticism.

Performance Rating can be defined as the procedure in which the time study engineer compares the performance of operator(s) under observation to the Normal Performance and determines a factor called Rating Factor.

System of Rating

There are several systems of rating the performance of operator on a job.

These are:

• Pace Rating

• Westinghouse System of Rating

• Objective Rating

• Synthetic Rating

A brief description of each rating method follows.

Pace Rating

Under this system, operator's performance is evaluated by considering his rate of accomplishment of the work. The study person measures the effectiveness of the operator against the concept of normal performance and then assigns a percentage to indicate the ratio of the observed performance to normal or standard performance.

In this method, which is also called the speed rating method, the time study person judges the operators speed of movements, i.e. the rate at which he is applying himself, or in other words "how fast" the operator performs the motions involved.

Westinghouse System of Rating

This method considers four factors in evaluating the performance of operator: skill, effort, conditions, and consistency.

Skill may be defined as the proficiency at of an individual in following the given method. It is demonstrated by co-ordination of mind and hands. A person's skill in a given operation increases with his experience on the job, because increased familiarity with work brings speed, smoothness of motions and freedom from hesitations.

The Westinghouse system lists six classes of each factor. For instance the classes of skill are poor, fair, average, good, excellent and superskill, as given in a Table . Each class has further two degrees. The time study person evaluates the skill displayed by the operator. And puts it in one of the six classes and also decides the degree in that class, higher or lower, i.e. 1 or 2. As equivalent % value of each class of skill is provided in the Table, the rating is translated into its equivalent percentage value, which ranges from +15 % (for super skill of higher degree) to -22 % (for poor skill of lower degree).

In a similar fashion, the ratings for effort, conditions, and consistency are given using the Table for each of the factors. By algebraically combining the ratings with respect to each of the four factors, the final performance-rating factor is estimated.

Objective Rating

In this system, speed of movements and job difficulty are rated separately and the two estimates are combined into a single value. Rating of speed or pace is done as discussed earlier, and the rating of job difficulty is done by selecting adjustment factors corresponding to characteristics of operation with respect to (i) amount of body used, (ii) foot pedals, (iii) bimanual ness, (iv) eye-hand co-ordination, (v) handling requirements and (vi) weight handled or resistance encountered. Mundel and Danner have given Table of % values (adjustment factors) for the effects of various difficulties in the operation performed.

For an operation under study, a numerical value for each of the six factors is assigned, and the algebraic sum of the numerical values called job difficulty adjustment factor is estimated.

The rating factor R can be expressed as

R = P x D

Where: P = Pace rating factor, and

D = Job difficulty adjustment factor.

Synthetic Rating

This method of rating has two main advantages over other methods. These are (i) it does not rely on the judgment of time study person and (ii) it gives consistent results.

The time study is made as usual. Some manually controlled elements of the work cycle are selected. Using a PMT system (Pre-determined motion time system), the times for these selected elements are determined. The times of these elements as determined are compared with the actual observed times and the performance factor is estimated for each of the selected elements.

Performance or Rating Factor, R = P / A

Where P = Predetermined motion time of the element, and

A = Average actual observed time of the element.

The overall rating factor is the mean of rating factors determined for the selected elements. This is applied uniformly to all the manually controlled elements of the work cycle.

Example

A work cycle has been divided into 8 elements and time study has been conducted. The average observed times for the elements are given in the following Table:

Element No.	1	2	3	4	5	6	7	8
Element Type	M	M	P	M	M	M	M	M
Average actual time (minutes)	0.14	0.16	0.30	0.52	0.26	0.45	0.34	0.15

M = Manually Controlled, P = Power Controlled

Total observed time of work cycle = 2.32 min.

Suppose we select three elements 2, 5 and 8 (These must be manually controlled elements). By using some PMT system, suppose we determine the times of these elements as

Elements No.	2	5	8
PMT System times (min)	0.145	0.255	0.145

Rating factor for element 2 = 0.145 / 0.16 = 90.62 %.

Rating factor for element 5 = 0.255 / 0.26 = 98.08 %.

Rating factor for element 8 = 0.145 / 0.15 = 96.66 %.

The mean of the rating factors of selected elements = 95.12 % or say 95 % is the rating factor that will be used for all the manual elements of the work cycle.

The normal time of the cycle can than be calculated as.

Element No.	1	2	3	4	5	6	7	8
Element Type	M	M	P	M	M	M	M	M
Average actual time (min)	0.14	0.16	0.30	0.52	0.26	0.45	0.34	0.15
PMT system time (min)		0.145			0.255			0.145
Performance Rating Factor	95	95	100	95	95	95	95	95

Normal Cycle Time

= 0.95(0.14+0.16+0.52+0.26+0.45+0.34+0.15) +1.00(0.30)

=1.92+0.30

=2.22 minutes

It is to be noted that power controlled (or machine-paced) elements are always given 100% rating.

Allowances

The readings of any time study are taken over a relatively short period of time. The normal time arrived at, therefore, does not include unavoidable delay and other legitimate lost time, for example, in waiting for materials, tools or equipment; periodic inspection of parts; interruptions due to legitimate personal needs, etc. It is necessary and important that the time study person applies some adjustment, or allowances, to compensate for such losses so that fair time standard is established for the given job.

Allowances are generally applied to total cycle time as some percentage of it, but sometimes these are given separately for machine time as some % and for manual effort time some other %. However, no allowances are given for interruptions which may be due to factors which are within the operator's control or which are avoidable.

Most companies allow the following allowances to their employees.

• Constant allowances (for personal needs and basic fatigue)

• Delay Allowance (for unavoidable delays)

• Fatigue Allowance (for job dependent fatigue)

• Personal Allowance

• Special Allowance

Delay Allowance

This time allowance is given to operator for the numerous unavoidable delays and interruptions that he experiences every day during the course of his work. These interruptions include interruptions from the supervisor, inspector, planners, expediters, fellow workers, production personnel and others. This allowance also covers interruptions due to material irregularities, difficulty in maintaining specifications and tolerances, and interference delays where the operator has to attend to more than one machine.

Fatigue Allowance

This allowance can be divided into two parts: (i) basic fatigue allowance and (ii) variable fatigue allowance. The basic fatigue allowance is given to the operator to compensate for the energy expended for carrying out the work and to alleviate monotony. For an operator who is doing light work while seated, under good working conditions and under normal demands on the sensory or motor system, a 4% of normal time is considered adequate. This can be treated as a constant allowance.

The magnitude of variable fatigue allowance given to the operator depends upon the severity of conditions, which cause extra (more than normal) fatigue to him. As we know, fatigue is not homogeneous. It ranges from strictly physical to purely psychological and includes combinations of the two. On some people it has a marked effect while on others, it has apparently little or no effect. Whatever may be the kind of fatigue-physical or mental, the result is same-it reduces the work output of operator. The major factors that cause more than just the basic fatigue includes severe working conditions, especially with respect to noise, illumination, heat and humidity; the nature of work, especially with respect to posture, muscular exertion and tediousness, and like that.

It is true that in modern industry, heavy manual work, and thus muscular fatigue is reducing day by day but mechanization is promoting other fatigue components like monotony and mental stress. Because fatigue in totality cannot be eliminated, proper allowance has to be given for adverse working conditions and repetitiveness of the work.

Personal Allowance

This is allowed to compensate for the time spent by worker in meeting the physical needs, for instance a periodic break in the production routine. The amount of personal time required by operator varies with the individual more than with the kind of work, though it is seen that workers need more personal time when the work is heavy and done under unfavorable conditions.

The amount of this allowance can be determined by making all-day time study or work sampling. Mostly, a 5 % allowance for personal time (nearly 24 minutes in 8 hours) is considered appropriate.

Special Allowances

These allowances are given under certain special circumstances. Some of these allowances and the conditions under which they are given are:

Policy Allowance: Some companies, as a policy, give an allowance to provide a satisfactory level of earnings for a specified level of performance under exceptional circumstance. This may be allowed to new employees, handicap employees, workers on night shift, etc. The value of the allowance is typically decided by management.

Small Lot Allowance: This allowance is given when the actual production period is too short to allow the worker to come out of the initial learning period. When an operator completes several small-lot jobs on different setups during the day, an allowance as high as 15 percent may be given to allow the operator to make normal earnings.

Training Allowance: This allowance is provided when work is done by trainee to allow him to make reasonable earnings. It may be a sliding allowance, which progressively decreases to zero over certain length of time. If the effect of learning on the job is known, the rate of decrease of the training allowance can be set accordingly.

Rework Allowance: This allowance is provided on certain operation when it is known that some percent of parts made are spoiled due to factors beyond the operator's control. The time in which these spoiled parts may be reworked is converted into allowance.

Different organizations have decided upon the amount of allowances to be given to different operators by taking help from the specialists / consultants in the field and through negotiations between the management and the trade unions. ILO has given its recommendations about the magnitude of various allowances, as shown in Table.

Example:

In making a time study of a laboratory technician performing an analysis of processed food in a canning factory, the following times were noted for a particular operation.

Run	1	2	3	4	5	6	7	8	9	10	11	12
Operation time (sec.)	21	21	16	19	20	16	20	19	19	20	40	19
Run	13	14	15	16	17	18	19	20	21	22	23	24
Operation time (sec.)	21	18	23	19	15	18	18	19	21	20	20	19

If the technician's performance has been rated at 120 percent, and the company policy for allowance (personal, fatigue, etc.) stipulates 13 percent,

• Determine the normal time.

• Determine the standard time.

Watch readings falling 50 % above and 25 % below the average may be considered as abnormal.

Ans:

Lecture 10

Work Sampling

Work Sampling (also sometimes called ratio delay study) is a technique of getting facts about utilization of machines or human beings through a large number of instantaneous observations taken at random time intervals. The ratio of observations of a given activity to the total observations approximates the percentage of time that the process is in that state of activity. For example, if 500 instantaneous observations taken at random intervals over a few weeks show that a lathe operator was doing productive work in 365 observations and in the remaining 135 observations he was found 'idle' for miscellaneous reasons, then it can be reliably taken that the operator remains idle (135/500) x 100 = 27 % 0f the time. Obviously, the accuracy of the result depends on the number of observations. However, in most applications there is usually a limit beyond which greater accuracy of data is not economically worthwhile.

Use of Work Sampling for Standard Time Determination

Work sampling can be very useful for establishing time standards on both direct and indirect labor jobs. The procedure for conducting work sampling study for determining standard time of a job can be described step-wise.

Step 1 . Define the problem.

• Describe the job for which the standard time is to be determined.

• Unambiguously state and discriminate between the two classes of activities of operator on the job: what are the activities of job that would entitle him to be in 'working" state.

This would imply that when operator will be found engaged in any activity other than those would entitle him to be in "Not Working" state.

Step 2. Design the sampling plan.

• Estimate satisfactory number of observations to be made.

• Decide on the period of study, e.g. two days, one week, etc.

• Prepare detailed plan for taking the observations.

This will include observation schedule, exact method of observing, design of observation sheet, route to be followed, particular person to be observed at the observation time, etc.

Step 3. Contact the persons concerned and take them in confidence regarding conduct of the study.

Step 4. Make the observations at the pre-decided random times about the working / not working state of the operator. When operator is in working state, determine his performance rating. Record both on the observation sheet.

Step 5. Obtain and record other information. This includes operator's starting time and quitting time of the day and total number of parts of acceptable quality produced during the day.

Step 6. Calculate the standard time per piece.

We will now briefly discuss some important issues involved in the procedure.

Number of Observations

As we know, results of study based on larger number of observations are more accurate, but taking more and more observations consumes time and thus is costly. A cost-benefit trade-off has thus to be struck. In practice, the following methods are used for estimation of the number of observations to be made.

(i) Based on judgment. The study person can decide the necessary number of observations based on his judgment. The correctness of the number may be in doubt but estimate is often quick and in many cases adequate.

(ii) Using cumulative plot of results. As the study progresses the results of the proportion of time devoted to the given state or activity, i.e. Pi from the cumulative number of observations are plotted at the end of each shift or day. A typical plot is shown in Figure. Since the accuracy of the result improves with increasing number of observations, the study can be continued until the cumulative Pi appears to stabilize and collection of further data seems to have negligible effect on the value of Pi.

(iii) Use of statistics. In this method, by considering the importance of the decision to be based on the results of study, a maximum tolerable sampling error in terms of confidence level and desired accuracy in the results is specified. A pilot study is then made in which a few observations are taken to obtain a preliminary estimate of Pi. The number of observations N necessary are then calculated using the following expression.

The number of observations estimated from the above relation using a value of Pi obtained from a preliminary study would be only a first estimate. In actual practice, as the work sampling study proceeds, say at the end of each day, a new calculation should be made by using increasingly reliable value of Pi obtained from the cumulative number of observations made.

Determination of Observation Schedule

The number of instantaneous observations to be made each day mainly depends upon the nature of operation. For example, for non-repetitive operations or for operations in which some elements occur in-frequently, it is advisable to take observations more frequently so that the chance of obtaining all the facts improves. It also depends on the availability of time with the person making the study. In general, about 50 observations per day is a good figure. The actual random schedule of the observations is prepared by using random number table or any other technique.

Design of Observation Sheet

A sample observation sheet for recording the data with respect to whether at the pre-decided time, the specified worker on job is in 'working' state or 'non-working' state is shown in Figure. It contains the relevant information about the job, the operators on job, etc. At the end of each day, calculation can be done to estimate the percent of time workers on the job (on an average) spend on activities, which are considered as part of the job.

Conducting Work Sampling Study

At the predecided times of study, the study person appears at the work site and observes the specific worker (already randomly decided) to find out what is he doing. If he is doing activity which is part of the job, he is ticked under the column 'Working' and his performance rating is estimated and recorded. If he is found engaged in an activity which is not a part of job, he is ticked under the column 'Not Working'. At the end of day, the number of ticks in 'Working' column is totaled and average performance rating is determined.

The observed time (OT) for a given job is estimated as

The normal time (NT) is found by multiplying the observed time by the average performing index (rating factor).

Where = is average rating factor to be determined as , Figure

The standard time is determined by adding allowances to the normal time.

Example

A work sampling study was made of a cargo loading operation for the purpose of developing its standard time. The study was conducted for duration of 1500 minutes during which 300 instantaneous observations were made at random intervals. The results of study indicated that the worker on the job was working 80 percent of the time and loaded 360 pieces of cargo during the study period. The work analyst rated the performance at 90 %. If the management wishes to permit a 13 % allowance for fatigue, delays and personal time, what is the standard time of this operation?

Ans:

Here, total study period = 1500 minutes

Working fraction = 80 percent

Average rating = 90 percent

Number of units loaded = 360

Allowances = 13 %

Advantages and Disadvantages of Work Sampling in Comparison with Time Study.

Advantages

Economical

• Many operators or activities which are difficult or uneconomical to measure by time study can readily be measured by work sampling.

• Two or more studies can be simultaneously made of several operators or machines by a single study person. Ordinarily a work study engineer can study only one operator at a time when continuous time study is made.

• It usually requires fewer man-hours to make a work sampling study than to make a continuous time study. The cost may also be about a third of the cost of a continuous time study.

• No stopwatch or other time measuring device is needed for work sampling studies.

• It usually requires less time to calculate the results of work sampling study. Mark sensing cards may be used which can be fed directly to the computing machines to obtain the results just instantaneously.

Flexible

6. A work sampling study may be interrupted at any time without affecting the results.

7. Operators are not closely watched for long period of time. This decreases the chance of getting erroneous results for when a worker is observed continuously for a long period, it is probable that he will not follow his usual routine exactly during that period.

Less Erroneous

8. Observations may be taken over a period of days or weeks. This decreases the chance of day-to-day or week-to-week variations that may affect the results.

Operators Like It

9. Work sampling studies are preferred to continuous time study by the operators being studied. Some people do not like to be observed continuously for long periods of time.

Observers Like It

10. Work sampling studies are less fatiguing and less tedious to make on the part of time study engineer.

Disadvantages

• Work sampling is not economical for the study of a single operator or operation or machine. Also, work-sampling study may be uneconomical for studying operators or machines located over wide areas.

• Work sampling study does not provide elemental time data.

• The operator may change his work pattern when he sees the study person. For instance, he may try to look productive and make the results of study erroneous.

• No record is usually made of the method being used by the operator. Therefore, a new study has to be made when a method change occurs in any element of operation.

• Compared to stop watch time study, the statistical approach of work sampling study is difficult to understand by workers.

Computerized Work Sampling

Use of a computer can save as much as 30 to 40 percent of the total work sampling study cost. This is because too much clerical effort is involved in summarizing work sampling data, e.g. in determining the number of observations required, determining the daily observations required, determining the number of trips to the area being studied per day, determining the time of each observation, calculating the accuracy of results, plotting data on control charts and like that. Computers can be used for mechanization of the repetitive calculations, display of control charts and calculation of daily as well as cumulative results.

Lecture 11

Predetermined Motion Time System

A predetermined motion time system (PMTS) may be defined as a procedure that analyzes any manual activity in terms of basic or fundamental motions required to perform it. Each of these motions is assigned a previously established standard time value and then the timings for the individual motions are synthesized to obtain the total time needed for performing the activity.

The main use of PMTS lies in the estimation of time for the performance of a task before it is performed. The procedure is particularly useful to those organizations which do not want troublesome performance rating to be used with each study.

Applications of PMTS are for

(i) Determination of job time standards.

(ii) Comparing the times for alternative proposed methods so as to find the economics of the proposals prior to production run.

(iii) Estimation of manpower, equipment and space requirements prior to setting up the facilities and start of production.

(iv) Developing tentative work layouts for assembly lines prior to their working in order to minimize the amount of subsequent re-arrangement and re-balancing.

(v) Checking direct time study results.

A number of PMTS are in use, some of which have been developed by individual organizations for their own use, while other organizations have developed and publicized for universal applications.

Some commonly used PMT systems are:

Work factor (1938)
Method Time Measurement (1948)
Basic Motion Time (1951)
Dimension Motion Time (1954)

Important considerations which may be made while selecting a PMT system for application to particular industry are:

Cost of Installation. This consists mainly of the cost of getting expert for applying the system under consideration.
Application Cost. This is determined by the length of time needed to set a time standard by the system under consideration.
Performance Level of the System. The level of performance embodied in the system under consideration may be different from the normal performance established in the industry where the system is to be used. However, this problem can be overcome by 'calibration' which is nothing but multiplying the times given in the PMT Tables by some constant or by the application of an adjustment allowance.
Consistency of Standards. Consistency of standards set by a system on various jobs is a vital factor to consider. For this, the system can be applied on a trial basis on a set of operations in the plant and examined for consistency in the so obtained operation times.
Nature of Operation. Best results are likely to be achieved if the type and nature of operations in the plant are similar to the nature and type of operations studied during the development of the system under consideration.

Advantages and limitations of using PMT systems

Advantages

Compared to other work measurement techniques, all PMT systems claim the following advantages:

There is no need to actually observe the operation running. This means the estimation of time to perform a job can be made from the drawings even before the job is actually done. This feature is very useful in production planning, forecasting, equipment selection, etc.
The use of PMT eliminates the need of troublesome and controversial performance rating. For the sole reason of avoiding performance rating, some companies have been using this technique.
The use of PMT forces the analyst to study the method in detail. This sometimes helps to further improve the method.
A bye-product of the use of PM times is a detailed record of the method of operation. This is advantageous for installation of method, for instructional purposes, and for detection and verification of any change that might occur in the method in future.
The PM times can be usefully employed to establish elemental standard data for setting time standards on jobs done on various types of machines and equipment.
The basic times determined with the use of PMT system are relatively more consistent.

Limitations

There are two main limitations to the use of PMT system for establishing time standards. These are: (i) its application to only manual contents of job and (ii) the need of trained personnel. Although PMT system eliminates the use of rating, quite a bit of judgment is still necessarily exercised at different stages.

Physiological Methods for Work Measurement

The physiological cost to an operator of performing any given physical work results from the activities of the muscles of arms, legs, back and other parts of the body and is, therefore, affected by the number and type of muscles involved in either moving the body member(s) or controlling antagonist contraction.

The activities of body muscles cause changes in oxygen consumption, heart rate, body temperature, lactic acid concentration in blood, 17-ketosteroid excretion in urine, pulmonary ventilation, and other factors. Studies have shown that some of these factors are only slightly affected by muscular activity. The important factors which have linear correlation with the physiological cost of work performed by an individual are oxygen consumption, heart rate, and pulmonary ventilation.

Increase in Heart Rate

When a person is at rest, his heart rate is at a fairly steady level (generally at about 70 beats/minute). Then when he starts doing some muscular work his pulse rate increases rapidly to about 110 beats/minute and remains near to this level during the working period. When work ends, the recovery begins and his heart rate drops off and finally returns to the original resting level ( Figure )

The increase in heart rate during work has been used as an index of the physiological cost of the job. Some physiologists have also proposed the use of 'the rate of recovery immediately after work stops' for the evaluation of physiological cost of certain types of work. It is to be noted that the total physiological cost of a task consists of the energy expenditure during work and the energy expenditure above the resting rate during the recovery period. It is generally agreed that the optimum limit of industrial performance is reached when the average pulse rate during the work lies 30 beats/minute above the resting pulse rate.

Measurement. With every heart beat, a small electric potential is generated. This signal can be picked up by placing silver electrodes on either side of the chest, and transmitted to a receiver, where these can be counted directly or recorded continuously on a ruled graph paper or integrated over time to measure in units of beats per minute with the help of a cardiotachometer.

Another method of getting the heart beat signals is through the use of an ear lobe unit, which is a photo duodiode with a light source. This unit is mounted on an ear of the subject in such a way that the duodiode is on one side and the light source is on the other side of the ear. As the capacity of the ear lobe changes due to the blood surges through the ear with beats of the heart, impulses are created which are transmitted and recorded.

A simple method to get the heart beat rate is through the use of a stethoscope and stop watch. Studies have shown that the data obtained in this manner are fairly reliable and also easy to obtain.

Oxygen Consumption. It may be defined as the volume of oxygen which a person extracts from the air he inhales. Increase in the rate of oxygen consumption from the resting level to the working level is also taken as a measure of the physiological cost of the work done. The oxygen consumption per unit time is usually measured indirectly. To do this the volume of air exhaled by a person in a certain time is collected and the oxygen content of this air is determined. For this, use is made of a portable respirometer. It is a lightweight gas meter which is worn on the back of the subject. A mask is fitted on the face of the subject, and the exhaled air is collected in the respirometer through a rubber tube. The respirometer directly shows the volume of exhaled air in litres.

A sample of the exhaled air is taken out at random intervals into a rubber bladder and an analysis is carried out of its content. Comparison is then made between the oxygen content of the two samples-drawn from the exhaled air and another from the room air. For each litre of oxygen consumed by the human body, there is an average energy turnover of 4.8 Kcal.

Table gives the general values of oxygen consumption, lung ventilation, rectal temperature and heart beats at the different work loads

Physiological measurements can be used to compare the energy cost to the operator on a job for which no time standard exists, with the energy cost to the same operator on a similar operation for which a satisfactory time standard already exists. By this comparison it is possible to establish the time standard on the job for which it does not exist already. For the sake of illustration, consider a job of lifting boxes weighing 2-3 kgs. from the floor level and placing it on a conveyor belt. For this job a time standard of 6 seconds (10 boxes/min.) is being used. When energy measurements were taken, it was found that to Mr. Singh, the operator on the job, the energy cost of this job was 300 W. Let us suppose now that there is another jab, similar to the first one, with the difference that here, the weight of the boxes is 5-6 kgs. If it is required to establish the t ime standard for this job, we need Mr. Singh to do this job of handling 5-6 kg. boxes at various speeds. From the energy cost data collected on him, we can select the speed of working that gives an energy cost of 300 W. So, by keeping the energy cost of the two jobs same, the time standard (the number of 5-6 kg. boxes/min.) can be determined.

sequencing theory

2012-09-17T07:15:00.004-07:00

Sequencing

Q1 how do scheduling activities differ for projects, mass production and process industries?
ANS
In the process industry continuous and batch production systems can be distinguished.There exists also semi-batch production which combines features from both. Plants producing only a limited number of products each in relatively high volume typically use special purpose equipment allowing a continuous flow of materials in long campaigns,i.e.,there is a continuous stream of input and output
products with no clearly defined start or end time.Alternatively,small quantities
of a large number of products are preferably produced using multi-purpose equipment which are operated in batch mode,i.e.,there is a well-defined start-up,e.g., filling in some products,well-defined follow-up steps defined by specific recipes, e.g.,heating the product,adding other products and let them react,and a clearly definedend,e.g.,extracting the finished product. Batch production involves an integer number of batches where a batch is the smallest quantity to be produced,e.g.,500 kg. Several batches of the same product following each other immediately establish a campaign. Production may be subject to certain constraints,e.g.,campaignsare built up by a discrete number of batches,or a minimal campaign length (or production quantity) has to be observed.Within a fixed planning horizon,a certain product can be produced in several campaigns; this implies that campaigns have to be modelled as individual entities.
Another special feature in the refinery or petrochemical industry or process
industry in general is the pooling problem ,an almost classical problem in nonlinear optimization. It is also known as the fuel mixture problem

Q2why is scheduling a job shop so difficult?

Ans:-Scheduling has become a critical factor in many job shops in order to determine their capacity for more work and be able to schedule their work more efficiently. Job shop scheduling becomes more and more difficult when you deal with assemblies and/or multiple components which need to be made in an efficient manner.
Job Shop Scheduling is an optimization problem in which ideal jobs are assigned to resources at particular times. The most basic version is as follows: We are given n jobs J1, J2, …Jn of varying sizes, which need to be scheduled on m identical machines, while trying to minimize the total length of the schedule (that is, when all the jobs have finished processing). Scheduling job shops is much more complex then the basic version above because there are many more constraints involved. In the above method the machines are identical which is not going to happen in an actual job shop. Online problem vs offline problem In an online scheduling system the scheduling application looks at a single piece of information at a time and does not know whats coming down the pipeline. In this situation the entire input is not known from the start. Because it does not know the whole input, an online algorithm is forced to schedule the job without knowledge of the entire input available at the start. The online algorithm needs to make a decision about that job before the next job is presented. In an offline scheduling system the scheduling application the system is given the whole problem data from the beginning and is required to answer scheduling problem given in an optimal way. Because an online scheduling system does not know the whole input, an online algorithm is forced to make decisions that may later turn out not to be optimal, and the study of online algorithms has focused on the quality of decision-making that is possible in this setting.
Q.no 3-
What the function are typically performed by a production control department ?

Ans –
Production control department responsibilities consist of
1. Loading—checking the availability of material, machines, and labour. The MRP system
plans for material availability. CRP converts the material plan into machine and
labour requirements, and projects resource overloads and under loads. Production
control assigns work to individual workers or machines, and then attempts to
smooth out the load to make the MRP schedule "doable." Smoothing the load is
called load levelling.
2. Sequencing—releasing work orders to the shop and issuing dispatch lists for individual
machines. MRP recommends when orders should be released (hence the name,
planned order releases). After verifying their feasibility, production control actually
Releases the orders. When several orders are released to one machine center, they must
be prioritized so that the worker will know which ones to do first. The dispatch list
contains the sequence in which jobs should be processed. This sequence is often based
on certain sequencing rules.
3. Monitoring—maintaining progress reports on each job until it is completed. This is
important because items may need to be rescheduled as changes occur in the system.
In addition to timely data collection, it involves the use of Gantt charts and input/output
control charts.
Q.no 4 –
Explain Johnsons rule and its Procedure .
Ans-Since few factories consist of just one process, we might wonder if techniques exist that will
produce an optimal sequence for any number of jobs processed through more than one
machine or process. Johnson's rule finds the fastest way to process a series of jobs through a
two-step system in which every job follows the same sequence through two processes. Based
on a variation of the SPT rule, it requires that the sequence be "mapped out" to determine
the final completion time, or makespan, for the set of jobs. The procedure is as follows:
1. List the time required to complete each job at each process. Set up a one-dimensional
matrix to represent the desired sequence with the number of slots equal to the number
of jobs.
2. Select the smallest processing time at either process. If that time occurs at process 1,
put the associated job as near to the beginning of the sequence as possible.
3. If the smallest time occurs at process 2, put the associated job as near to the end of the
sequence as possible.
4. Remove the job from the list.
5. Repeat steps 2-4 until all slots in the matrix have been filled or all jobs have been
sequenced.
Question 5

What is PRIORITY SEQUENCING

Choice of right sequencing rule based on one criteria criteria
becomes quite critical as no singular rule is ideal for all situations
some of the criteria used are :
Set-up cost or change over cost
Work in progress inventory cost
Idle time
No. of jobs late
No. of jobs early
Average no. of jobs
Average flow time
Average time to complete a job

SINGLE CRITERIA PRIORITY SEQUENCING RULES

1. First come first serve (FCFS)

2. Shortest processing time(SPT) this rule minimize the WIP
inventory cost and at same time the throughput time

3. Longest processing time (LPT) jobs having longest processing
time are scheduled first

4. Least slack rule Highest priority is given to the job which had
least slack
Slack= available time-processing time

5. Earliest due date(EDD) the jobs having their earliest due date
given highest priority

6. Preferred Customer order

7. Random selection

8. (TSPT) this rule sequence the jobs acc. To the SPT except the
jobs have been waiting for a time period longer than a specified
truncated time are given higher priority than other jobs

9. COVERT it uses the ratio of expected delay cost to the
processing time
COVERT=expected delay cost/processing time

10. Least change over cost priority is given by analyzing the
total cost of the making machine change over cost b/w the jobs

Question 6
What are sequenceing rules ? How are they evaluated?
EVALUATION OF SEQUENCING RULES:

1. Average job flow time is define as the total time spent by job
in system
Average job flow time =job waiting time +job processing
time

2. Average no. of jobs flowing in the system (waiting or being
processed from the beginning of sequencing when the last
job is finished

3. Average job lateness is defined as the diff. b/w the actual
completion time of job and its due date.

4. Average earliness of job if a job is completed before its due
date the lateness value is –ve and its magnitude is referred as
job earliness of the job

5. No.of tardy jobs
No. of jobs which are completed after the due date

7. What three functions are typically performed by a production control department?

Process Planning (Routing)

The determination of where each operation on a component part, subassembly, or assembly is to
be performed results in a route for the movement of a manufacturing lot through the factory.
Prior determination of these routes is the job of the manufacturing engineering function.

Loading

Once the route has been established, the work required can be loaded against the selected
machine or workstation. The total time required to perform the operation is computed by
multiplying the unit operation times given on the standard process sheet by the number of parts
to be processed. This total time is then added to the work already planned for the workstation.
This is the function of loading, and it results in a tabulated list or chart showing the planned
utilization of the machines or workstations in the plant.

Scheduling

Scheduling is the last of the planning functions. It determines when an operation is to be
Performed, or when work is to be completed; the difference lies in the detail of the scheduling
procedure.

8.Give the type of operations (manufacturing or service) and suggest which scheduling objectives might be appropriate for each ?

In a manufacturing content, intermittent systems are traditionally referred to as Job-Shops. As the work order arrive , the work load on the facility increases.Some work centres may be idle at the same time that orders are severely overloaded. A work centre may experience a large build-up of orders awaiting processing.
The sequencing in which the waiting jobs are processed is critical to the efficiency and the effectiveness of the intermittent system. Sequencing affects how many jobs are completed on time versus late , costs incurred for setup and change-over , delivery load times , inventory costs , and the degree of congestion on the facility.

SERVICES

Intermittent systems may be used in both the product and service organizations. In the restaurants and the automobile repair shops for example conversion systems are similar to concept to those in manufacturing job-shops.

Q 10- What information is provided by the critical sequencing rule? How does it differ from Slack?
Ans- Variations on the DDATE rule include minimum slack and the smallest critical ratio. Slack considers the work remaining to be performed on a job as well as the time remaining (until due date) to perform that work. Jobs are processed first that have the least difference between the two as follows:
SLACK = (due date-today’s date)-(remaining processing time)
The critical ratio uses the same time as slack but arranges it in ratio form so that scheduling performance can be easily assessed. Mathematically, the CR is calculated as follows:
CR= time remaining = due date-today’s date
Work remaining remaining processing time
If the work remaining is greater than the time remaining, the critical ratio will be less than1. If the time remaining is greater than the work remaining, the critical ratio will be greater than 1. If the time remaining equals work remaining, the critical ratio exactly equals 1. The critical ratio allows us to make the following statements about our schedule:
If CR>1, then the job is ahead of schedule
If CR<1, then the job is behind schedule
If CR=1, then the job is exactly on schedule

Q12 What are gantt charts & why are they used so often ?
Ans-- A Gantt chart is a type of bar chart that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project.Terminal elements and summary elements comprise the work breakdown structure of the project.Gantt charts also show the dependency (i.e., precedence network) relationships between activities. Gantt charts can be used to show current schedule status using percent-complete shadings.
Gantt charts have become a common technique for representing the phases and activities of a project work breakdown structure (WBS), so they can be understood by a wide audience all over the world.

Q.NO.13 EXPLAIN THE CONCEPT BEHIND INPUT/OUTPUT CONTROL. DESCRIBE HOW GATEWAYWORK CENTERS, DOWNSTREAM WORK CENTERS,AND BACKLOG EFFECT SHOP PERFORMANCE?
ANS: Input/output is a technique that allows operation to manage facility work flow. It is used to control the size of the queues in front of work centres, thereby helping to control manufacturing lead times. Refer to as "push system" of linking work centres. When batch of items is completed at one work centre, it is pushed to the next work centre, where it waits in a queue until it is selected to be worked at that work centre.
Input-output Control is important because it is a form of queue control, and a great
portion of the time that a job spends in a plant is spent waiting in queues. In many job shops
Input-output Control is used to monitor and control the amount if work in a queue at a work
centre so that it stays within reasonable bounds. Queue times, therefore, are more consistent
and predictable. The actual output, in standard hours of works, that flows from a work centre
is the demonstrated actual capacity of the centre.
If the capacity differs from the planned amount of work over a few scheduling periods,
the problem needs to be investigated. If the work that flows to work centre is greater than the
actual output, the queue in front of the centre will grow. On the other words, If the works is
arriving faster than it is being processed, we are overloading the facility and a backlog
develop.Overloading causes crowding in the facility, leading to inefficiencies and quality
problem. If the works is arriving at a slower rate than it is being performed, we are
underloading the facility and the work centre may run out of work. Underloading the facility
results in idle capacity and wasted resources.

Q.no.14 EXPLAIN THE DIFFERENCE BETWEEN FINITE AND INFINITE SCHEDULING??
ANS: Finite Scheduling
Scheduling type within capacity planning that takes account of the capacity loads which already exist. Finite scheduling calculates the start and finish dates for operations in the order. It is a detailed scheduling strategy with which you schedule orders and operations, taking into account the existing resource load. A resource overload cannot occur.
Infinite Scheduling
A detailed scheduling strategy with which you schedule orders and operations, without taking into account the existing resource load. It is therefore possible for resource overloads to occur.
R/3 does planning without consideration for capacity situations. So if MRP says you need 500 parts on 3/1/04, it schedules them all to be built at the same time, even though you can only do 100 at a time. Assume you have a fixed lot size of 100, you'll get 5 planned orders for 100 to start on the same day. This is "Infinite Planning". APO would recognize that constraint, and instead schedule out the 5 orders over time. The important part of that is that it also will schedule out the deliveries of the components for 5 different days. This is "Finite Planning".
Now, assume old fashion MRP. It schedules all 5 orders for the same day, and the buyers go out an get all of the components for the same day. Then the planner realizes he can't do all 5, and manually changes the schedule, and manually spreads out the 5 orders. The buyers will recieve rescheduling notifications, but not until the scheduler does the manual rescheduling.
You could call this "Infinite Scheduling", but that only means the same thing as Infinite Planning.
15 How does theory of constraints differ from traditional scheduling?
Sol-THE THEORY OF CONSTRAINTS
The theory of constraints is a philosophy that has a lot in common with Just-in-Time but also has some critical differences. There are two basic differences. The first is that the theory of constraints accepts the existence of a constraint, at least temporarily, and focuses the improvement effort on the constraint and related workstations. The second is that the theory of constraints uses overlapped production (transfer batch not equal to the process batch) to schedule work through a batch production environment, while Just-in-Time provides no scheduling mechanism for a batch environment. Thus, the theory of constraints scheduling approach has wider applicability than Just-in-Time (although Just-in-Time's continuous improvement philosophy and quality emphasis clearly is applicable to batch production environments).
There are five steps to the theory of constraints: identify the constraint, exploit it, subordinate everything else to it, elevate the constraint, and avoid inertia when the constraint shifts. In exploiting the constraint, the drum-buffer-rope scheduling technique and buffer management are used. In finding ways to elevate the constraint, the techniques of effect-cause-effect and the cloud diagram often are useful.

Traditional scheduling

Long before there was absolute priority, Unix systems were scheduling the CPU using this system. When Posix came in like the Romans and imposed absolute priorities to accommodate the needs of realtime processing, it left the indigenous Absolute Priority Zero processes to govern themselves by their own familiar scheduling policy.
Indeed, absolute priorities higher than zero are not available on many systems today and are not typically used when they are, being intended mainly for computers that do realtime processing. So this section describes the only scheduling many programmers need to be concerned about.
But just to be clear about the scope of this scheduling: Any time a process with a absolute priority of 0 and a process with an absolute priority higher than 0 are ready to run at the same time, the one with absolute priority 0 does not run. If it's already running when the higher priority ready-to-run process comes into existence, it stops immediately.
In addition to its absolute priority of zero, every process has another priority, which we will refer to as "dynamic priority" because it changes over time. The dynamic priority is meaningless for processes with an absolute priority higher than zero.
The dynamic priority sometimes determines who gets the next turn on the CPU. Sometimes it determines how long turns last. Sometimes it determines whether a process can kick another off the CPU.
In Linux, the value is a combination of these things, but mostly it is just determines the length of the time slice. The higher a process' dynamic priority, the longer a shot it gets on the CPU when it gets one. If it doesn't use up its time slice before giving up the CPU to do something like wait for I/O, it is favored for getting the CPU back when it's ready for it, to finish out its time slice. Other than that, selection of processes for new time slices is basically round robin. But the scheduler does throw a bone to the low priority processes: A process' dynamic priority rises every time it is snubbed in the scheduling process. In Linux, even the fat kid gets to play.
The fluctuation of a process' dynamic priority is regulated by another value: The “nice” value. The nice value is an integer, usually in the range -20 to 20, and represents an upper limit on a process' dynamic priority. The higher the nice number, the lower that limit.
On a typical Linux system, for example, a process with a nice value of 20 can get only 10 milliseconds on the CPU at a time, whereas a process with a nice value of -20 can achieve a high enough priority to get 400 milliseconds.
The idea of the nice value is deferential courtesy. In the beginning, in the Unix garden of Eden, all processes shared equally in the bounty of the computer system. But not all processes really need the same share of CPU time, so the nice value gave a courteous process the ability to refuse its equal share of CPU time that others might prosper. Hence, the higher a process' nice value, the nicer the process is. (Then a snake came along and offered some process a negative nice value and the system became the crass resource allocation system we know today).
Dynamic priorities tend upward and downward with an objective of smoothing out allocation of CPU time and giving quick response time to infrequent requests. But they never exceed their nice limits, so on a heavily loaded CPU, the nice value effectively determines how fast a process runs.
In keeping with the socialistic heritage of Unix process priority, a process begins life with the same nice value as its parent process and can raise it at will. A process can also raise the nice value of any other process owned by the same user (or effective user). But only a privileged process can lower its nice value. A privileged process can also raise or lower another process' nice value.
16 what are some typical issues involved in employee scheduling?
Sol- Top 5 Challenges Caused by Traditional Employee Scheduling

Manual Staff Scheduling has Low ROI
Creating an employee schedule by hand is a daunting task for managers and supervisors. Matching worker availability to staffing requirements and controlling labor costs at the same time is complicated. When managers produce a schedule manually, they often end up causing inflated payroll in some areas while leaving other departments chronically understaffed.
Worse yet, achieving this sub-optimal result usually takes over 8 hours per week just to create a schedule for 70-100 workers. A manager who takes employee scheduling seriously may spend much more time on this task – up to 14 hours per week. Still, the outcome can be disappointing simply because this method is inefficient.

Employees Aren’t Kept Up to Speed
In today’s dynamic production environments, last minute changes are common. This means you have probably noticed the following problem with manually created employee schedules: workers are frequently unaware of last minute changes. That’s because they have no visibility in their schedules. This causes unintended time & attendance violations that managers and HR staff members have to investigate and address.
When an employee doesn’t show up to cover his/her shift, other workers must stay longer. This increases your overtime costs. Or, you have to cope with the inevitable problems caused by running a shift with a skeleton crew.
In addition to being confused by the lack of a transparent staff scheduling process, employees may also become resentful. It isn’t unusual for workers to feel that covert decisions regarding time off requests and shift scheduling are being made out of favouritism.

Payroll Errors Eat Up Valuable Resources
When it comes to getting timesheets turned in to Payroll, the problems with manual employee scheduling become even more evident. Each timesheet has to be tediously compared with logged hours. Managers must review each sheet after the fact, correct it, and send the edits to Payroll. This is not a productive use of time for your department heads. Of course, if a busy manager makes an error in editing, payroll employees have to edit (by hand) again.

Unbudgeted Expenses Cause Conflict
A decentralized, manual scheduling process makes it tough to keep staffing expenses and unapproved overtime under control. This is a common cause of unbudgeted departmental expenditures. Without real-time access to staffing data, current schedules, and budgeting parameters, managers have difficulty finding the most suitable, cost efficient employee to fill a gap. They have no choice but to make an uninformed decision and cope afterward with the consequences of incurring unbudgeted expenses.

Labor Law Compliance Risks
Inconsistency and poor record keeping are the most common offenses that trigger fines for labor law and worker pay violations. Without visibility in employee scheduling (and complete, accurate records), HR may be unaware of a problem until it is too late. This not only puts your company at risk for being penalized by government agencies, it also opens you up to litigation from employees.

Q:17
What quantitative techniques are available to help employee schedule & advanced planning and scheduling system ?
ANS:
Employee scheduling has lots of option because labor is a very flexible resource .The assignment method of linear programming is designed for employee scheduling problem of assign worker with difference performance rating available.Large scale linear programming is currently used by Mc Donald to schedule its large contingents.
Most employee scheduling problems are solved by heuristics (rules of thumb):
Employee scheduling heuristics
1. N= no. of worker
D = demand of workers
X = Day working
O = Day off
2. Assign the first N- D1 worker day1 off, assign next N-D2 worker 2 off and similar to next .
3. If no. of worker is less than 5 , assign the remaining workers so that consecutive days off are possible
4. Assign any remaining work to part time employee .
5. If consecutive dayoff desire consider switching scheduling among days with same demand requirements .
Q: 18
Look for advanced planning and scheduling software on the internet .write the summary of the techniques presents .
ANS:
Advanced planning and scheduling (also referred to as APS )a refers to a manufacturing management process by which raw materials and production capacity are optimally allocated to meet demand. APS is especially well-suited to environments where simpler planning methods cannot adequately address complex trade-offs between competing priorities . APS simultaneously plans and schedules production based on available materials, labor and plant capacity.
APS has commonly been applied where one or more of the following conditions are present:
1. Make-To-Order (as distinct from make-to-stock) manufacturing
2. capital-intensive production processes, where plant capacity is constrained
3. products 'competing' for plant capacity: where many different products are produced in each facility
4. products that require a large number of components or manufacturing tasks .
Advanced Planning & Scheduling software enables manufacturing scheduling and advanced scheduling optimization within these environments.
Advantages:
•Includes advanced scheduling features like overlap, storage constraints, and custom constraints.
•Gives the look-and-feel of Microsoft products for easy usage.
•Manages all constraints by taking into account materials, machines, labor, and tooling.
•Infinitely customizes activity labels on our powerful Resource Gantt and Job Gantt.
•Shows resource utilization and availability by looking at an organized Capacity Plan graph and grid.
•Highlights problems, like bottlenecks, in red so you’ll never miss a scheduling conflict again

sequencing numericals

2012-09-17T07:14:00.003-07:00

Q1. At valley hospital nurses beginning a new shift report to a central area to receive their primary assignments. not every nurses is as efficient as another with particular kinds of patients. Given the following patient roster care levels, and time estimates, assign nurses to patients to optimize efficiency. Also, determine how long it will take for nurses to complete their routine tasks on the shift.

atpatient	Care level	Nurse1	Nurse2	Nurse3	Nurse4
Jones	A2	3	5	4	3
hathaway	B2	2	1	3	2
bryant	B1	3	4	2	2
sweeney	A1	4	3	3	4

ANS

	Nurse1	Nurse2	Nurse3	Nurse4
A2	0	2	1	0
B2	1	0	2	1
B1	1	2	0	0
A1	1	0	0	1

B2	N2
A1	N3
B1	N4
A2	N1

Time take

N1 take 3

N2 take 1

N3 take 3

N4 take 2

Q2. Valley hospital wants to focus on customer perceptions of quality , so it has asked its patients to evaluate the nursing staff and indicate preference for assignment. Reassign the nursing staff to obtain the highest customer approval rating possible .

Patient	Nurse1	Nurse2	Nurse3	Nurse4
A Jones	89	95	83	84
B Hathaway	88	80	96	85
C Bryant	87	92	82	84
D Sweeney	93	82	86	94

ANS

	N1	N2	N3	N4
A	6	1	13	12
B	8	16	0	11
C	9	4	14	12
D	3	14	10	2

	N1	N2	N3	N4
A	5	0	12	11
B	8	16	0	11
C	5	0	10	8
D	1	12	8	0

	N1	N2	N3	N4
A	4	0	12	11
B	7	16	0	11
C	4	0	10	8
D	0	12	8	0

N1= A

N2=C

N3=B

N4=D

Q.no 3-

Ans -

Item	1	2	3	4	5
Chocolate Mint	30	18	26	17	15
Peanut Butter	23	22	32	25	30
Short Bread	17	31	24	22	29
Fudge Delight	28	19	13	18	23
Macarooons	23	14	16	20	27

Matrix :

30	18	26	17	15
23	22	32	25	30
17	31	24	22	29
28	19	12	18	23
23	14	16	20	27

15	3	11	2	0
1	0	10	3	8
0	14	7	5	12
15	6	0	5	10
9	0	2	6	13

Crosses line not equal to order of matrix so,

15	3	11	0	0
1	0	10	1	8
0	14	7	3	12
15	6	0	3	10
9	0	2	4	13

15	3	11	0	0
0	0	10	0	7
0	15	7	3	12
15	7	0	3	10
9	0	2	4	13

Item
Chocolate Mint	5
Peanut Butter	4
Short Bread	1
Fudge Delight	3
Macarooons	2

Q. no -4

Answer –

Product	A	B	C	D	E
1	17	10	15	16	20
2	12	9	16	9	14
3	11	16	14	15	12
4	14	10	10	18	17
5	13	12	9	15	11

Matrix :

3	10	5	4	0
8	11	4	11	6
9	4	6	5	8
6	10	10	2	3
7	8	11	5	9

3	10	5	4	0
4	7	0	7	2
5	0	2	1	4
4	8	8	0	1
2	3	6	0	4

A	B	C	D	E
1	10	5	4	0
2	7	0	7	2
3	0	2	1	4
2	8	8	0	1
0	3	6	0	4

E	1
C	2
B	3
D	4
A	5

Answer

Questn 9

s.p.t.	typing	proofing
1	-30	20
2	90	25
3	60	15
4	-45	30
5	75	60
6	-20	30

Sol.

Chap	Typing	Proofing
6	20	30	20
1	30	20	50
4	45	30	95
6	60	15	155
5	75	60	230
2	90	25	320

Total completion time=320 days

Avg. Flow time=(20+50+95+155+230+320)/6

=145 days.

Avg. No. Of jobs each in same days=1.22days

Avg. Job lateness=(0+20+50+95+155+230)/6

=91.6 days

10.


1	8	5
2	15	10
3	6	5
4	5	10
5	17	15
6	10	10
7	5	3
8	4	15
9	12	10
10	20	3


8	4	4	15
4	5	9	10
7	5	14	3
3	6	20	5
1	8	28	5
6	10	38	10
9	12	50	10
2	15	65	10
5	17	52	15
10	20	92	3

time completion=92 days

avg. Flow time=40.2

avg. No. Of jobs in same day=41.2

avg. Job lateness=32.1

Question 11-jobs processed through Percy machine shop pass through three operation milling, grinding and turning. the hours required for each of these operation is as follow:-

Sequence the operation and make the Gantt chart:-

Jobs	Milling	Grinding	Turning
A	5	1	4
B	2	2	5
C	3	2	1
D	0	3	0
E	4	1	2

Q 12- Given that all the jobs listed below must be machined first, then polished, determine a sequence that will minimize the time required to process all 6 jobs. Chart the schedule on a gantt chart and indicate the makespan.

Jobs	MACHINING	POLISHING
A	5.0	4.0
B	7.0	3.0
C	3.0	2.0
D	2.0	1.0
E	2.0	3.0

F 6.0 5.0

Ans- Idle time for M1= 1 min

Idle time for M2= 4 min

ASSIGNMENT QUESTIONS

Q13 .Given the prep. And painting time in days for following five houses.Chart out your sequence on gantt charts and calculate the makespan.

Houses	Prep.	Paint
Addison	4	2
Brown	3	6
Clayton	6	4
Daniels	5	6
Ebersole	1	4

ANS—

Q14. Sequence the houses in previous problem by SPT and SLACK.How much time is saved with johnsons rule ?

ANS-- SLACK

Time saved= 27-23=4

SPT

Time saved=25-23=2

Q.15 Job A,B,C, & D must be processed through the same machine centre .Sequence the following Jobs by

a.SPT

b. SLACK

JOB	PROCESSING TIME	DUE DATE
A	20	20
B	10	15
C	30	50
D	15	30

Calculate the mean flow time ,mean tardiness and max tardiness .which sequencing rule would you recommend? Why?

Ans:

According to

SPT

JOB	PROCESSING TIME	DUE DATE	FLOW TIME
B	10	15	1 0
D	15	30	25
A	20	20	45
C	30	50	75

According to slack rule

JOB	PROCESSING TIME	DUE DATE	FLOW TIME	SLACK
A	20	20	45	0
B	10	15	1 0	5
D	15	30	25	15
C	30	50	75	20

RULE	TOTAL COMPLETION TIME	AVG. TIME FLOW	AVG. NO. OF JOBS	AVG. JOB LATENESS	AVG. JOB EARLINESS	NO. OF TARDI JOBS
SPT	75	38.7	2.066	12.5	2.5	3
SLACK	75	38.7	2.23	13.75	0	3

Mean tardiness = 0.75

Maximum tardiness = 3

Shortest Path time sequencing is preferred because in this case avg. Job lateness is less and avg. Job earliness is more.

Q.16 Sequence the following jobs by (a)SPT (b)DDATE, and (c)SLACK .Calculate the mean flow time mean tardiness and max tardiness .which sequencing rule would you recommend? Why?

JOB	PROCESSING TIME	DUE DATE
A	5	8
B	3	5
C	9	18
D	6	7

Sol.

SPT:

JOB	PROCESSING TIME	DUE DATE	FLOW TIME
B	3	5	3
A	5	8	8
D	6	7	14
C	9	9	23

Avg. Flow time = (3+8+14+23)/4 = 8.75

No. of tardi jobs = 2

SLACK:

JOB	PROCESSING TIME	DUE DATE	FLOW TIME
C	9	9	9
D	6	7	15
B	3	5	18
A	5	8	23

Avg. Flow time = (9+15+18+23)/4 = 16.25

No. of tardi jobs = 3

DUE DATE:

JOB	PROCESSING TIME	DUE DATE	FLOW TIME
B	3	5	3
D	6	7	9
A	5	8	14
C	9	18	23

Avg. Flow time = (3+9+14+23)/4 = 12.25

No. of tardi jobs = 2

JOB	AVG. FLOW TIME	NO. OF TARDI JOBS	MAX. TARDINESS
SPT	8.75	2	14
SLACK	16.25	3	15
DUE DATE	12.25	3	6

17 Complete the report

period	1	2	3	4	5	total
Planned input	50	55	60	65	65	295
Actual input	50	50	55	60	65	280
Deviation	0	-5	-5	-5	0	-15
Planned output	65	65	65	65	65	325
Actual output	60	60	60	60	60	300
Deviation	-5	-5	-5	-5	-5	-15
Backlog 30	20	10	5	5	10

18 complete the table

Period	1	2	3	4	5	total
Planned input	50	55	60	65	65	295
Actual input	40	50	55	60	65	270
Deviation	-10	-5	-5	-5	0	-25
Planned output	50	55	60	65	65	295
Actual output	50	50	55	60	65	280
Deviation	0	-5	-5	-5	0	-15
Backlog 10	0	0	0	0	0

Q: 19

Kim jonshan R.N. the charge nurse of the antepartum ward of city hospital , need help in scheduling the nurse workforce for next work.

(1) Create the employee schedule that will meet the demand requirements &garuntee each nurse 2 days off per week.

ANS:

Day of week	Mo	Tu	We	Th	Fr	St	su
No of nurse	3	3	4	5	4	3	3
Kim jonshan	O	X	X	X	X	O	x
Tom swan	O	X	X	X	X	O	x
Flo cology	X	O	X	X	X	X	o
Shelli	X	O	X	X	X	X	o
Troung	X	X	O	X	O	X	x

(2) Revise the schedule so that 2 days off are consecutive.

ANS:

Day of week	Mo	Tu	We	Th	Fr	St	su
No of nurse	3	3	4	5	4	3	3
Kim jonshan	o	o	x	x	x	x	x
Tom swan	O	O	x	X	X	X	X
Flo cology	X	X	O	X	O	X	X
Shelli	X	X	X	X	X	O	o
Troung	x	x	X	x	x	o	o

Here o = off days

X= working day

Flo cology not have consecutive off days .

Q 20:

Rosemary needs help in scheduling volunteers . create a work schedule that will meet the requirements ,given that a volunteer will only work 4 days per week .try to make the work consecutive.

Days of weeks	Mo	Tu	We	Th	Fr	St	Su
No. of volunteers	4	3	2	3	6	4	2
Rosemary
Albert
Richard
Gail
Shelly
Karen

ANS:

Days of weeks	Mo	Tu	We	Th	Fr	St	Su
No. of volunteers	4	3	2	3	6	4	2
Rosemary	O	O	O	X	X	X	X
Albert	O	O	O	X	X	X	X
Richard	X	O	O	X	X	X	O
Gail	X	X	O	O	X	X	O
Shelly	X	X	X	O	X	O	O
Karen	X	x	x	O	x	O	O

3 Consecutive offdays possible for only 2 volenteer &for remaining 2 consecutive off days .

Q21

Job	1	2	3	4	5	6
M/C 1	25	30	60	20	35	45
M/C 2	25	15	40	25	30	70

Find idle time, flow time and total time using gantt chart.

Ans 1

Sequence-- 4 6 3 5 1 2

Idle time – machine 1 –30

Machine 2 – 40

Total time -- 245

Q22

Job	M1	M2	M3	M4
A	7	11	2	14
B	18	15	18	13
C	4	11	14	18
D	14	27	32	21
E	6	16	14	16

Ans 2

M1-M4

M1+M2--M3+M4

M1+M2+M3—M2+M3+M4

Q.no 10-

What the function are typically performed by a production control department ?

Ans –

Production control department responsibilities consist of

1. Loading—checking the availability of material, machines, and labour. The MRP system

plans for material availability. CRP converts the material plan into machine and

labour requirements, and projects resource overloads and under loads. Production

control assigns work to individual workers or machines, and then attempts to

smooth out the load to make the MRP schedule "doable." Smoothing the load is

called load levelling.

2. Sequencing—releasing work orders to the shop and issuing dispatch lists for individual

machines. MRP recommends when orders should be released (hence the name,

planned order releases). After verifying their feasibility, production control actually

Releases the orders. When several orders are released to one machine center, they must

be prioritized so that the worker will know which ones to do first. The dispatch list

contains the sequence in which jobs should be processed. This sequence is often based

on certain sequencing rules.

3. Monitoring—maintaining progress reports on each job until it is completed. This is

important because items may need to be rescheduled as changes occur in the system.

In addition to timely data collection, it involves the use of Gantt charts and input/output

control charts.

Q.no 11 –

Explain Johnsons rule and its Procedure .

Ans-Since few factories consist of just one process, we might wonder if techniques exist that will

produce an optimal sequence for any number of jobs processed through more than one

machine or process. Johnson's rule finds the fastest way to process a series of jobs through a

two-step system in which every job follows the same sequence through two processes. Based

on a variation of the SPT rule, it requires that the sequence be "mapped out" to determine

the final completion time, or makespan, for the set of jobs. The procedure is as follows:

1. List the time required to complete each job at each process. Set up a one-dimensional

matrix to represent the desired sequence with the number of slots equal to the number

of jobs.

2. Select the smallest processing time at either process. If that time occurs at process 1,

put the associated job as near to the beginning of the sequence as possible.

3. If the smallest time occurs at process 2, put the associated job as near to the end of the

sequence as possible.

4. Remove the job from the list.

5. Repeat steps 2-4 until all slots in the matrix have been filled or all jobs have been

sequenced.

Q.no 3-

Ans -

Item	1	2	3	4	5
Chocolate Mint	30	18	26	17	15
Peanut Butter	23	22	32	25	30
Short Bread	17	31	24	22	29
Fudge Delight	28	19	13	18	23
Macarooons	23	14	16	20	27

Matrix :

30	18	26	17	15
23	22	32	25	30
17	31	24	22	29
28	19	12	18	23
23	14	16	20	27

15	3	11	2	0
1	0	10	3	8
0	14	7	5	12
15	6	0	5	10
9	0	2	6	13

Crosses line not equal to order of matrix so,

15	3	11	0	0
1	0	10	1	8
0	14	7	3	12
15	6	0	3	10
9	0	2	4	13

15	3	11	0	0
0	0	10	0	7
0	15	7	3	12
15	7	0	3	10
9	0	2	4	13

Item
Chocolate Mint	5
Peanut Butter	4
Short Bread	1
Fudge Delight	3
Macarooons	2

Q. no -4

Answer –

Product	A	B	C	D	E
1	17	10	15	16	20
2	12	9	16	9	14
3	11	16	14	15	12
4	14	10	10	18	17
5	13	12	9	15	11

Matrix :

3	10	5	4	0
8	11	4	11	6
9	4	6	5	8
6	10	10	2	3
7	8	11	5	9

3	10	5	4	0
4	7	0	7	2
5	0	2	1	4
4	8	8	0	1
2	3	6	0	4

A	B	C	D	E
1	10	5	4	0
2	7	0	7	2
3	0	2	1	4
2	8	8	0	1
0	3	6	0	4

E	1
C	2
B	3
D	4
A	5

2012-09-17T07:10:00.001-07:00

Q.no 1-

What the function are typically performed by a production control department ?

Ans –

Production control department responsibilities consist of

1. Loading—checking the availability of material, machines, and labour. The MRP system

plans for material availability. CRP converts the material plan into machine and

labour requirements, and projects resource overloads and under loads. Production

control assigns work to individual workers or machines, and then attempts to

smooth out the load to make the MRP schedule "doable." Smoothing the load is

called load levelling.

2. Sequencing—releasing work orders to the shop and issuing dispatch lists for individual

machines. MRP recommends when orders should be released (hence the name,

planned order releases). After verifying their feasibility, production control actually

Releases the orders. When several orders are released to one machine center, they must

be prioritized so that the worker will know which ones to do first. The dispatch list

contains the sequence in which jobs should be processed. This sequence is often based

on certain sequencing rules.

3. Monitoring—maintaining progress reports on each job until it is completed. This is

important because items may need to be rescheduled as changes occur in the system.

In addition to timely data collection, it involves the use of Gantt charts and input/output

control charts.

Q.no 2 –

Explain Johnsons rule and its Procedure .

Ans-Since few factories consist of just one process, we might wonder if techniques exist that will

produce an optimal sequence for any number of jobs processed through more than one

machine or process. Johnson's rule finds the fastest way to process a series of jobs through a

two-step system in which every job follows the same sequence through two processes. Based

on a variation of the SPT rule, it requires that the sequence be "mapped out" to determine

the final completion time, or makespan, for the set of jobs. The procedure is as follows:

1. List the time required to complete each job at each process. Set up a one-dimensional

matrix to represent the desired sequence with the number of slots equal to the number

of jobs.

2. Select the smallest processing time at either process. If that time occurs at process 1,

put the associated job as near to the beginning of the sequence as possible.

3. If the smallest time occurs at process 2, put the associated job as near to the end of the

sequence as possible.

4. Remove the job from the list.

5. Repeat steps 2-4 until all slots in the matrix have been filled or all jobs have been

sequenced.

Q.no 3-

Ans -

Item	1	2	3	4	5
Chocolate Mint	30	18	26	17	15
Peanut Butter	23	22	32	25	30
Short Bread	17	31	24	22	29
Fudge Delight	28	19	13	18	23
Macarooons	23	14	16	20	27

Matrix :

30	18	26	17	15
23	22	32	25	30
17	31	24	22	29
28	19	12	18	23
23	14	16	20	27

15	3	11	2	0
1	0	10	3	8
0	14	7	5	12
15	6	0	5	10
9	0	2	6	13

Crosses line not equal to order of matrix so,

15	3	11	0	0
1	0	10	1	8
0	14	7	3	12
15	6	0	3	10
9	0	2	4	13

15	3	11	0	0
0	0	10	0	7
0	15	7	3	12
15	7	0	3	10
9	0	2	4	13

Item
Chocolate Mint	5
Peanut Butter	4
Short Bread	1
Fudge Delight	3
Macarooons	2

Q. no -4

Answer –

Product	A	B	C	D	E
1	17	10	15	16	20
2	12	9	16	9	14
3	11	16	14	15	12
4	14	10	10	18	17
5	13	12	9	15	11

Matrix :

3	10	5	4	0
8	11	4	11	6
9	4	6	5	8
6	10	10	2	3
7	8	11	5	9

3	10	5	4	0
4	7	0	7	2
5	0	2	1	4
4	8	8	0	1
2	3	6	0	4

A	B	C	D	E
1	10	5	4	0
2	7	0	7	2
3	0	2	1	4
2	8	8	0	1
0	3	6	0	4

E	1
C	2
B	3
D	4
A	5

AMBASSADOR LIFE CYCLE

2012-09-17T07:04:00.002-07:00

Production Planning & Control

Assignment

AMBASSADOR LIFE CYCLE

Submitted to Submitted by

Babu lal

IPE department

Brand : Ambassador

Company : Hindustan Motors

High time

Ambassador can be called as an first indian car. Although car has an British legacy, it is considered as definitive Indian car. Ambassador was born in 1958. The car owes its design and technology to a British car model - Morris Oxford which was built by Morris Motor Co at Oxford UK. Hindustan Motors launched the Indian version of Morris Oxford as Ambassador in 1958.

From 1958 to 1980's Ambassador ruled the Indian market. Infact there were only two cars in the Indian market - Premier Padmini and Ambassador. The license raj, lack of capital and the unfriendly Indian economic policies ensured that no automobile manufacturers entered the Indian market.

Ø Unmatched space, comfort, safety and sturdiness

Once the uncrowned king of Indian roads, the Ambassador has been relegated to the ranks of also-rans by the new brigade of Japanese, Korean, European and American cars.

Ø It was the only Indian car with Diesel option. During those times, there was a significant difference in the prices between Diesel and Petrol.

Ø Second advantage was the space and sturdiness of the Amby. These two factors enabled the brand to become popular among big families and more importantly among the Taxi and tour operators.

But consumers bought the car because of the significant economy of diesel cars which made consumers to compromise on other parameters.

If we look at the product, Ambassador never changed with times. The brand made many cosmetic changes from 1958-2000 and three upgrades was made which was named as Mark II, Mark III and Mark IV . There was no significant value addition between these upgrades. The look and the built quality remained the same. A major change happened when the brand introduced a 1800 Isuzu engine. The Amby with Isuzu again lifted the sales of the brand.

Isuzu engine

Ø Another significant market for Ambassador was the Government. Over 16 % of the brand sales came from the Government. Ambassador was the first choice for most bureaucrats. Ambassador used to be the Prime Minister's car till 2002.

But the euphoria was short lived.

Low time

Ø That status was lost when the PM of that time Mr Atal Bihari Vajpai replaced Ambassador with a BMW Limo.

Soon the officials also lost interest in the brand. With the emergence of new and better models from other auto-makers, there was a significant drop in the orders from the Government.

The fall of Ambassador from a leadership position to a marginal player is a classic case of marketing myopia. For four decades, the brand has been taking its customers for granted. There are many reasons that can be attributed to this brand's failure. The fundamental issue was with the product and price.

Ø The apathy of HM to offer product changes in tune with the times made the brand stale.

Ø Second factor that failed Amby was the price. HM never bothered to rationalize the price of the brand. Even now Ambassador costs more than Rs 4,80,000. At that price one could afford a better SUV and can roam with pride.

Ø The nail in the coffin came with the launch of Indica. Indica took away the taxi car market from Ambassador. Again the diesel loving individual consumers had a better affordable modern car as compared to the ageing Ambassador.

In order to lift the sagging sales of the brand, HM launched a radically designed Ambassador variant Avigo in 2004. Although the styling was radical, the customer response was lukewarm.

Ambassador avigo

Indian consumer is now spoilt with choices. The competition is immense and the quality of cars has also gone up. Consumers now have new set of purchase considerations like quality, brand, drivability, luxury, cost of maintenance etc

In the value proposition domain, Ambassador is never in the radar of the consumers. The narrowing price difference between petrol and diesel also eroded the value in investing in an old dated Ambassador.

Ø The company also has never invested in the brand. Without investing in either brand or product, HM had sealed the fate of this brand. The question that arise is could a brand like Ambassador maintain its position Indian market despite all the competition?

In the brand management perspective, its suicidal not to continuously invest in a brand .Often heritage brands wait till it becomes dated. Once the brand becomes dated, its virtually impossible to rejuvenate the brand. The task is to prevent the brand to become dated. For that the brand has to go to the consumer for ideas. Changes in product or promotions can sustain the brand even in the light of emerging competition. Brands like Lux , lifebuoy, Surf has been successful because of continuous investment in branding and product development.

1983 saw the emergence of a new era in the Indian car market. Maruti Udyog Ltd launched the Maruti 800. Soon Ambassador lost its leadership position to Maruti. The family segment which is the largest segment in the car market embraced Maruti. Ambassador was reduced to a marginal player within no time.

Ø Ambassador should have learned from Maruti 800. The brand is still surviving because it made changes along with the changing consumer values. Also the brand rationalized its price in the light of emerging competition which made Maruti 800 relevant even in the current market. But now maruti has also stopped its production and now focusing on other cars.

I am not saying that Amby had the potential to become an Iconic brand like Volkswagen, BMW, mercedes, Audi . But the brand could have been relevant to Indian market as a basic family car. It is a herculean task to bring Ambassador back to life. A price below the price of Indica is the only option for the brand to keep its fortunes alive.

Amby was perceived to be a sturdy car ideal for Indian roads. The brand also had a positive perception of being less expensive to maintain. These two were only perceptions .

Ø In fact Ambassador was expensive to maintain and even though the car looked sturdy and well built, the car lacked the quality and refinement.

Ø Rattling sounds and rusting was common complaints.

Sales graph

Efforts made

HM decides to increase sales of their age old classic model – Ambassador in the country.

Ø They are planning to sell 12,500 units this year with the introduction of their new fuel efficient engine. This engine will be compliant with the Bharat Stage 2 & 3 emission norms. It’s probably delivering the mileage of 16 km/l against a 11 km/l mileage from the existing diesel engine.

Ø Hindustan Motors plans to invest Rs 6 crores in upgrading engines to build them BS-3 compliant. The number of changes will be made on the new model.

Ø HM also has introduced the buy-back scheme where buyers can exchange their old models of Ambassador with the new one at the discount of Rs 35K.

HM’s 50-years old model is presently being made by the industry in Uttarpara, Kolkata. This model is available as 1.5L CNG and petrol version and 2L diesel engine variants. Currently, the car has majority sales in Delhi, west Bengal, tamil Nadu and Kerala. It has the 110 dealers across India.

Its makers, Hindustan Motors, have been making valiant attempts to re-invent the car as a Contemporary classic, much in the mould of Enfield (Bullet) motorcycles, but have been much less successful in their efforts.

I have seen by their sales figures that they still manage to sell a couple of thousand cars a year even today. Beats me why anyone would want an AMBY, except for old times’ sake. When I was growing up, it was the car to own, since it was cheaper to maintain than a Fiat, had a better turning radius (5.4m), could go anywhere, could carry more people and luggage and last, but not the least, could be repaired even by a roadside dabbah-wallah!

According to reports, the HM plant had achieved full depreciation in 2000. But the company did not thought of passing on the reduced cost to the consumer. Had the company rationalised the price of Amby in 2000 and did some renovation to its product, the brand could have survived the competition.

Electric Resistance Welding,Types of extrusion,Indirect extrusion or backward extrusion

2011-04-29T11:25:00.000-07:00

Electric Resistance Welding

It is a type of pressure welding. It is used for joining pieces of sheet metal or wire. The welding heat is obtained at the location of the desired weld by the electrical resistance through the metal pieces to a relatively short duration, low voltage, high ampere electric current. The amount of current can be regulated by changing the primary turns of the transformer. When the area to be welded is sufficiently heated, the pressure varying from 25MPa to 55MPa is applied to the joining area by suitable electrodes until the weld is solid. The various types of electric resistance welding are as follows:

(1) Spot welding

It is used for welding lap joints, joining components made from plate material having 0.025 to 1.25 mm in thickness. The plate to be joined together are places between the two electrode tips of copper or copper alloy.

(2) Roll spot and seam welding

When the spot welds on two over lapping pieces of metal are spaced, the process of welding is known as roll spot welding. If the spot welds are sufficiently made close, then the process is called seam welding. This process is best for metal thickness ranging from 0.0.25 to 3 mm.

(3) Projection welding

It is similar to spot welding except that one of the metal pieces to be welded has projections on its surface at the points, Where the welds are to be made. In other words it is a multi spot welding process.

(4) Butt welding

The butt welding is of two type :

· Upset butt welding

· Flash butt welding

The upset butt welding is especially adopted to rods, pipes and many other components of uniform sections. The flash butt welding is extensively used in the manufacture of steel containers and in the welding of mild steel shanks to high speed drills and reamers

Extrusion Processes:

Extrusion is the process of confining the metal in a close cavity and then allowing it to flow from only one opening , so that the metal will take the shape of the opening. The operation is identical to the sequeezing of toothpaste out of the toothpaste tube.

By the extrusion process, it is possible to make component which have a constant cross section over any length as can be formed by the rolling process. Some typical parts can be extruded are shown:

Compexity of parts that can be obtain by extrusion is more than that of rolling, because the die required being very simple and easier to make. Also extrusion is a single pass process,unlike rolling the amount of reduction that si possible in extrusion is large. Generally brittle materials can be very easily extruded. It is also possible to produce sharp corners and different angles. It is possible to gets shapes with internal cavaties in extrusion by the use of spider die. Large diameters, thin walled , tubler products with execellent concentricity and tolerance charasitic can be produced.

Types of extrusion:

1: Direct extrusion or forward extrusion

2: Indirect extrusion or backward extrusion

Indirect extrusion or backward extrusion

In order to completely overcome the problem, the backward hot extrusion as shown in figure, in this process the metal is confined fully by the cylinder, the ram which houses the die also compresses the metal against the container , forcing it to flow backward to the die in the hollow plunger or ram.

It is termed backward because of the opposite direction of the flow of the metal. Thus the billet in the container remains stationary and hence produce no friction. Also the extrusion pressure is not effected by the length. In the extrusion press since the friction is not loss. The figure of the backward extrusion is shown;

Direct Extrusion or Forward Extrusion

The equipment consists of a cylinder or container into which the heated metal billet is loaded. One end of the container, the die plate with necessary opening is fixed. From the other end plunger or ram compresses the metal billet against the container walls and die plate, thus the forcing it to flow of metal in the forward direction through the die opening.

Acquiring the shape of the opening the extruded metal is then carried by the metal is then carried b the metal handling system as it comes out of the die. A dummy block which is a steel disc of about 40mm thick with a diameter slightly less than container is kept between the hot billet and the ram to protect it form heat and pressure. In direct extrusion, the problem of friction prevalent because of the relative motion between heated metal billet and cylinder walls. To reduce this friction lubricants are to be used. To reduce the damage to equipment, extrusion is finished quickly and the cylinder is cooled before further extrusion.

2011-04-29T11:19:00.001-07:00

Electric Resistance Welding

(1) Spot welding

(2) Roll spot and seam welding

(3) Projection welding

(4) Butt welding

The butt welding is of two type :

· Upset butt welding

· Flash butt welding

Moulding sand properties and its classification: ,,Shell moulding ;

2011-04-29T11:16:00.000-07:00

Moulding sand properties and its classification:

The moulding is a process of making a cavity or mould out of sand by means of a pattern. The molten metal is poured into the moulds to produce casting.

Properties of moulding sand

1: porosity or permeability

It is the property of sand which permits the steam and other gases to pass through the sand mould. The porosity of sand depends upon its grain size, grain shape, moisture and clay components are the moulding sand. If the sand is too fine, the porosity will be low.

2: Plasticity

It is that property of sand due to which it flows to all portions of the moulding box or flask. The sand must have sufficient plasticity to produce a good mould.

3: Adhesiveness

It is that properties of sand due to it adheres or cling to the sides of the moulding box.

4: Cohesiveness

It is the property of sand due to which the sand grains stick together during ramming. It is defined as the strength of the moulding sand.

5: Refractoriness

The property which enables it to resist high temperature of the molten metal without breaking down o r fusing.

Classification of Moulding sand according to their use:

1: Green sand

The sand in its natural or moist state is called green sand. It is also called tempered sand. It is a mixture of sand with 20 to 30 percent clay, having total amount of water from 6 to 10 percent. The mould prepared with this sand is called green sand mould, which is used for small size casting of ferrous and non-ferrous metals.

2: Dry Sand

The green sand moulds when baked or dried before pouring the molten metal are called dry sand moulds. The sand of this condition is called dry sand. The dry sand moulds have greater strength, rigidity and thermal stability. These moulds used for large and heavy casting.

3: Loam Sand

A mixture of 50 percent sand grains and 50 percent clay is called loam sand. It is used for loam moulds of large grey iron casting.

4: Facing Sand

A sand which is used before pouring the molten metal, on the surface is called facing sand. It is specially prepared sand from silica sand and clay.

5: Backing or Floor Sand

A sand used to back up the facing sand and not used next to the pattern is called backing sand. The sand which have been repeatedly used may be employed for this purpose. It is also known as black sand due to its colour.

6: System Sand

A sand employed in mechanical sand preparation and handling system is called system sand. This sand has high strength, permeability and refractoriness.

7: Parting Sand

A sand employed on the faces of the pattern before the moulding is called parting sand. The parting sand consists of dried silica sand, sea sand or burnt sand.

8: Core Sand

The cores are defined as sand bodies used to form the hollow portions or cavities of desired shape and size in the casting. Thus the sand used for making these cores is called core sand. It is sometimes called oil sand. It is the silica sand mixed with linseed oil or any other oil as binder.

Shell moulding ;

It is a process in which the sand is mixed with a thermo setting resin is allowed to come into contact a heated metallic pattern plate ‘so that a them and strong shell of mould is formed around the pattern’ then she is removed the pattern and the cope and drag are remove together and kept in a flask with the necessary back up material and the molten metal is pored into the mould.

Generally dry and fin sand which is completely free of the clay is used for preparing the shell mould in are the phenol formaldehyde rising combined with sand they hare very high strength and resistance through heat.

Steps Involve;

Step 1;

A metal pattern having the profile of the required casting is heated to 180°-260°c in an own maintained at 300°-400°c pattern after being heated is taken out of the own and sprayed with a solution of a lubricating agent containing silicon. It is necessary to prevent the shell from sticking to the metal pattern.

Step 2:

Metal pattern(made up of iron or steel )is then turned faced down and clamped over the open end of the dump box.

Step 3:

the dump box is inverted so that dry sand raisin mixture falls on the face of hot metal pattern . the raisin the raisin softens and fuses to form a soft and uniform sand mixture in contact with the pattern gets heat up .the rasinsoftens and fuses to form a soft and uniform shell of about 6mm thickness on the surface of pattern.

Step 4;

As the dump box is turned to its original position. Excess sand resin mixture falls beak into the dump box leaving a shell adhering closely to the pattern

Step 5;

The shell is then stripped from the pattern plate with the help of ejector pins which are an integral part of the metal pattern

Step 6;

After the shells so obtained have cooled. Two meeting shell are securely fastened together to from a complete mould.

2011-04-29T11:12:00.002-07:00

Casting Defects:

The defects in a casting may be due to pattern and moulding box equipment, moulding sand, cores,gating system or molten metal. Some of the defects are:

1: Mould shift

It results in a mismatching of the top and the bottom parts of the casting , usually at the parting line.

2: Swell

It is an enlargement of the mould cavity by molten metal pressure resulting in localized or general enlargement of the casting.

3: Fins and Flash

These are thin projections of the metal not intended as a part of casting. These usually occurs at the parting line of the mould.

4: Sand Wash

It usually occurs near the in the gates as rough lumps on the surface of a casting.

5: Shrinkage

It is a crack or breakage in the casting on the surface of the work piece, which results from un equal contraction of the metal during solidification.

6: Hot Tear

It is an internal or external ragged discontinuously in the metal casting resulting just after the metal has solidified.

7: Sand Blow or Blow Hole

It is smooth depression on the outer surface of the casting work piece.

8: Honeycombing or Slag holes

These are smooth depression on the upper surface of the casting. They usually occur near the ingates.

9: Scabs

These are patches of sand on the upper surface of the casting component.

10: Cold Shut and Misruns

These happens when the mould cavity is not completely filled by the molten and insufficient material or metal.

11: Run-outs and Bust-outs

These permit drainage of the metal from the cavity and result in incomplete casting.

Casting Defects: Forging defects:

2011-04-29T11:12:00.000-07:00

Casting Defects:

The defects in a casting may be due to pattern and moulding box equipment, moulding sand, cores,gating system or molten metal. Some of the defects are:

1: Mould shift

It results in a mismatching of the top and the bottom parts of the casting , usually at the parting line.

2: Swell

It is an enlargement of the mould cavity by molten metal pressure resulting in localized or general enlargement of the casting.

3: Fins and Flash

These are thin projections of the metal not intended as a part of casting. These usually occurs at the parting line of the mould.

4: Sand Wash

It usually occurs near the in the gates as rough lumps on the surface of a casting.

5: Shrinkage

It is a crack or breakage in the casting on the surface of the work piece, which results from un equal contraction of the metal during solidification.

6: Hot Tear

It is an internal or external ragged discontinuously in the metal casting resulting just after the metal has solidified.

7: Sand Blow or Blow Hole

It is smooth depression on the outer surface of the casting work piece.

8: Honeycombing or Slag holes

These are smooth depression on the upper surface of the casting. They usually occur near the ingates.

9: Scabs

These are patches of sand on the upper surface of the casting component.

10: Cold Shut and Misruns

These happens when the mould cavity is not completely filled by the molten and insufficient material or metal.

11: Run-outs and Bust-outs

These permit drainage of the metal from the cavity and result in incomplete casting.

Forging defects:

Though forging process give generally prior quality product compared other manufacturing processes. There are some defects that are lightly to come a proper care is not taken in forging process design.

A brief description of such defects and their remedial method is given below.

(A): Unfilled Section:

In this some section of the die cavity are not completely filled by the flowing metal. The causes of this defects are improper design of the forging die or using forging techniques.

(B): Cold Shut:

This appears as a small cracks at the corners of the forging. This is caused manely by the improper design of die. Where in the corner and the fillet radie are small as a result of which metal does not flow properly into the corner and the ends up as a cold shut.

(C): Scale Pits:

This is seen as irregular depurations on the surface of the forging. This is primarily caused because of improper cleaning of the stock used for forging. The oxide and scale gets embedded into the finish forging surface. When the forging is cleaned by pickling, these are seen as depurations on the forging surface.

(D): Die Shift:

This is caused by the miss alignment of the die halve, making the two halve of the forging to be improper shape.

(E): Flakes:

These are basically internal ruptures caused by the improper cooling of the large forging. Rapid cooling causes the exterior to cool quickly causing internal fractures. This can be remedied by following proper cooling practices.

(F): Improper Grain Flow:

This is caused by the improper design of the die, which makes the flow of the metal not flowing the final interred direction.

Arc Welding and its different processes

2011-04-29T11:10:00.000-07:00

Arc Welding:

The arc welding is a fusion welding process in which the welding heat is obtained from an electric arc struck between the work(or base metal) and an electrode. The temperature of the heat produced by the electric arc is of the order of 6000°C to 7000°C. Both the direct current (D.C) and alternating current(A.C) may be used for arc welding, but the direct current is preferred for most purposes. When the work is connected to the positive terminal of the D.C welding machine and the negative terminal to an electrode holder, the welding set up is said to have straight polarity. On the other hand, when work is connected to negative and the electrode to a positive terminal, then the welding set up is said to have reversed polarity. The straight polarity is preferable for some welds while for other welds reversed polarity should be used.

Following are the two types of arc welding depending upon the type of electrode:

(A): Un shielded arc welding:

When a large electrode or filler rod is used for welding, it is said to be un- shielded arc welding.

(B): Shielded arc welding:

When the welding rods coated with fluxing material are used, then it is called shielded arc welding.

Arc welding Processes:

The following are the various welding processes commonly used in engineering practice.

1: Carbon arc welding

In carbon arc welding, the welding heat is obtained from an electric arc between a carbon electrode and the work. In welding heavy plants, the additional metal is deposited in the weld from a filler rod.

2: Metal arc welding

In metal arc welding , the arc is produced between the metal electrode(also called filler rod) and the work piece. During the welding process, the metal electrode is melted by the heat of the arc and fused with the work piece. The temperature produced by the heat is about 2400° C to 2700° C.

3: Metallic inert gas (MIG) Arc welding:

In MIG welding , the electrode is consumable, the filler metal is deposited by the arc which is completely surrounded by an inert gas.

4: Tungsten inert gas(TIG) arc welding

In TIG welding, the heat is produced from an arc between the non consumable tungsten electrode and the work piece. The welding zone is shielded by an atmosphere of inert gas(such as helium or argon) supplied from a suitable source. The direct current with a straight polarity is used for welding copper alloys and stainless steel. Whereas the reversed polarity is used for magnesium. The alternating current is more versatile in welding for steel, cast iron, aluminum and magnesium.

5: Atomic hydrogen welding

In atomic hydrogen welding, the arc is obtained between two tungsten electrodes (non consumable) while a stream of hydrogen passes by the arc and envelopes the welding zone.

6: Stud arc welding

It is a direct current arc welding process, and is used for welding metal studs to the flat metal surfaces.

7: Submerged arc welding

In submerged welding, the arc is produced between a bare metal electrode and the work piece. The submerged arc welding is mostly done on low carbon and alloy steels, but it may be used on many of the non-ferrous metals.

8: Thermit welding

In this welding, a mixture of iron oxide and aluminum known as thermit, is used. The mixture is ignited only at a temperature of about 1500°C. A major advantage of the thermit welding is that all parts of the weld section are molten at the same time and the weld cools almost uniformly. This results in a minimum problem with internal residual stresses. The thermit welding is often used in joining iron and steel parts that are too large to be manufactured, such as rails, trucks frames, locomotive frames, other large sections used on steam and rail roads, for stern frames, rubber frames etc. In steel mills, Thermit electric welding is employed to replace broken gear teeth, to weld new necks on rolls and pinions and to repair broken shears.

Forging and its types,Forging defects:

2011-04-26T11:31:00.000-07:00

Forging and its types

Forging is the operation where the metal is heated and then a force is applied to manipulates the metals in such a way that the required final shape is obtained. Forging is generally a hot working process through cold forging is used sometimes.

Type of forging

1. smith forging

2. drop forging

3. press forging

4. machine forging

1: Smith forging

This is the traditional forging operation done openly or in-openly dies by the village black smith or modern shop floor by manual hammering or by the power hammer. The process involves heating the stock in the black smith hearth and then beating it over the anvil. To get the desire shape the operator has to manipulate the component in between the blows.

The types of operation available are fullering, flattering, bending , upsetting and swaging.

2: Drop forging

Basic definition:

This is the operation done in closed impression dies by means drop hammer here the force for shaping the component is applied in a series of blows.

Drop forging utilizes a closed impression die to obtain the desire shape of the component , the shaping is done by the repeated hammering given to the material in the die cavity. The equipment use for delivering for blows are called drop hammers. The drop forging die consists of two halves. The lower halve of the die is fixed to the anvil of the machine , while the upper halve is fixed to ram. The heated stock is kept in the lower die, while the ram delivers 4-5 blows on the metal spreads and completely fills in the die cavity. When the two die of halves closed the complete is formed. The typical products obtained in drop forging are cranks, crank shaft, connecting rods, wrench, crane hooks etc. The types of operations are fullering, edging, bending, blocking , finishing and trimming etc.

3: Press forging

Similar to the drop forging , the press forging is also done in closed impression dies with the expectation that the force is continuous squeezing type applied by the hydraulic press. Press forging dies are similar to drop forging dies as also the process in press forging, the metal is shaped not by means of a series of blows as in drop forging , but by means of a single continuous squeezing action. This squeezing is obtained by means of hydraulic presses. Because of the continuous action of by hydraulic presses, the material gets uniformly deform through out its entire depth ,the press forging dies with the various impression , such as fuller, bender and finisher impression properly arranged .

4: Machine forging:

Unlike the press or drop forging where the material is drawn out , in machine forging the material is only upset to get the desire shape. As it involves the upsetting operation some time it is simply called as upset forging. Originally this was develop for making bolts head in a continuous fashion, but now there are fairly large number of diverse.

Uses of this process:

Because of the beneficial grain flow obtain from upsetting. It is used for making gears, blanks, shafts, excels, and similar parts. Upsetting machine called up setter are generally horizontal acting. The die set consists of die and corresponding punch or a heading tool. The die consists of two parts, one called the stationary gripper die which is fixed to the machine frame and the other movable gripper die which moves along with the die slide of the up setter. The stock is held then between these two gripper dies.

The upset forging cycle start with the, movable die sliding against the stationary die to grip the stock. The two dies when in closed position from the necessary die cavity then the heading tool advance against the stock and upset it to completely filled to the die cavity.

Having completed the upsetting the heading tool moves back to its back position. Then the movable gripper die releases the stock by sliding backward. Similar to drop forging it is not possible to get the final shape in a single pass in machine forging also. Therefore the operation is carried out in number of stages. The die cavities is required for the various operations are all arrange vertically on the gripper dies. The stock is the move from stage one to another in proper sequence till the final forging is ready. A heading tool each for every upsetting stage is arranged on the heading slide of the upsetting machine. A typical upsetting die and heading tool is shown:

Forging defects:

A brief description of such defects and their remedial method is given below.

(A): Unfilled Section:

In this some section of the die cavity are not completely filled by the flowing metal. The causes of this defects are improper design of the forging die or using forging techniques.

(B): Cold Shut:

(C): Scale Pits:

(D): Die Shift:

This is caused by the miss alignment of the die halve, making the two halve of the forging to be improper shape.

(E): Flakes:

(F): Improper Grain Flow:

This is caused by the improper design of the die, which makes the flow of the metal not flowing the final interred direction.

Forging operations:

2011-04-26T10:50:00.000-07:00

Forging operations:

1: Drawing:

This is the operation in which metal gets elongated with a reduction in the cross sedation area. For this, a force is to be applied in a direction perpendiaulant to the length axis.

2:Up setting:

This is applied to increase the cross seat ional area of the stock at the expanse of the length. To achieve the length of upsetting force is applied in a direction parallel to the length axis, For example forming of a bolt head.

3:Fullering:

It a similar to material cross-section is decreased and length increased. To do this; the bottom fuller is kept in angle hole with the heated stock over the fuller .the top fuller is then kept above the stock and then with the sledge hammer, and the force is applied on the top fuller.

4:Edging:

It is a process in which the metal piece is displaced to the desired shape by striking between two dies edging is frequently as primary drop forging operation.

5:Bending:

Bending is very common forging operation. It is an operation to give a turn to metal rod or plate. This is required for those which have bends shapes.

6:Punching:

It is a process of producing holes in motel plate is placed over the hollow cylindrical die. By pressing the punch over the plate the hole is made.

7:Forged welding: It is a process of joining two metal pieces to increase the length. By the pressing or hammering then when they are at for ging temperature.Itis performed in forging shop and hence is called forged welding.

8:Cutting:

It is a process in which a metal rod or plate cut out into two pieces, with the help of chisel and hammer, when the metal is in red hot condition.

9:Flating and setting down:

Fullering leaves a corrugated surface on the job. Even after a job is forged into shape with a hammer, the marks of the hammer remains on the upper surface of the job. To remove hammer marks and corrugation and in order to obtain a smooth surface on the job, a flatter or set hammer is used.

10: Swaging:

Swaging is done to reduce and finish work for desire size and shape, usually either round or hexagonal. For small jobs top and bottom swage pair is employed, where as for large work swage block can be used.


8	4	4	15
4	5	9	10
7	5	14	3
3	6	20	5
1	8	28	5
6	10	38	10
9	12	50	10
2	15	65	10
5	17	52	15
10	20	92	3


8	4	4	15
4	5	9	10
7	5	14	3
3	6	20	5
1	8	28	5
6	10	38	10
9	12	50	10
2	15	65	10
5	17	52	15
10	20	92	3


8	4	4	15
4	5	9	10
7	5	14	3
3	6	20	5
1	8	28	5
6	10	38	10
9	12	50	10
2	15	65	10
5	17	52	15
10	20	92	3