Gundopant

Welding guns 101: light- or heavy-duty?

2012-07-25T06:44:00.001-07:00

Welding guns 101: light- or heavy-duty?

Which semiautomatic GMAW gun is right for the job?

October 4, 2010

From tacking operations that require short arc-on times to completing long, continuous welds on thick plate, the welding gun needs to offer the appropriate welding capacity for the job.

Figure 1Light-duty GMAW guns work well for applications requiring tacking or short arc-on times.

When it comes to choosing welding equipment, welding operators may find themselves contemplating which power source to use—and rightly so. The power source significantly affects weld quality, productivity, and overall costs of welding. But having the correct semiautomatic gas metal arc welding (GMAW) gun for the job is equally important.

From tacking operations that require short arc-on times to completing long, continuous welds on thick plate, the gun needs to offer the appropriate welding capacity for the job. For example, welding operators may not need a GMAW gun that is the same amperage as the power source. That is because often they weld only 30 to 50 percent of the time, making the use of a lower-amperage gun an appropriate option. Conversely, an overworked light-duty gun could fail prematurely. Or if a welding operation involves varied applications, the gun must be able to address the needs of all of them.

On the Lighter Side

For welding applications that require short arc-on times, such as tacking or small-part welding, a light-duty GMAW gun may be the best choice (seeFigure 1). A light-duty gun is typically considered one that provides from 100 to 300 amps of welding capacity. Like all guns, light-duty ones are rated according to their duty cycle, or the number of minutes in a 10-minute period that the gun can be operated at its full capacity without overheating. Generally, gun manufacturers rate their products at 60 to 100 percent duty cycle.

For applications such as welding sheet metal, general hobbyist projects, and auto repair and autobody work, a light-duty gun works well. Because light-duty guns typically have low amperage capacity, they also tend to be smaller and lighter than higher-duty ones, making them easy to maneuver even in tight areas. Most have small, compact handles that are comfortable for most operators.

Such guns often use light- or standard-duty consumables, including nozzles, contact tips, and retaining heads (or gas diffusers). These consumables generally have less mass and are less expensive than their heavy-duty counterparts. Designed for short arc-on times, the necks (or goosenecks) are made of lightweight materials such as polymer, rubber, or light aluminum armor.

The gun's strain relief usually consists of a flexible rubber component or in some cases may be absent altogether. These features reduce the gun's weight, but it also makes it susceptible to kinking, which may lead to poor wire feeding and gas flow. Damage to the crimped connections on some unicables can be especially problematic. If a crimped connection becomes damaged, the cable or possibly the entire gun may need to be replaced.

Generally, light-duty guns offer standard features at a low price and typically need to be replaced more frequently.

Figure 2Heavy- duty GMAW guns provide the necessary durability to accommodate continuous and multiple-pass welding.

Guns for Tougher Jobs

Some jobs require long arc-on times or multiple passes on thick sections. Such jobs are found in heavy-equipment manufacturing for the agriculture, construction, trucking, and mining industries. For these applications, heavy-duty guns are the best choice, as they can weld continuously on 1-inch or thicker material and in harsh environments typical in such industries (see Figure 2).

Heavy-duty guns generally are rated between 400 and 600 amps and are available in both air- and water-cooled models. The choice between a water- or air-cooled heavy-duty gun largely depends on the welding application, operator preference, and cost considerations. Water-cooled systems are more expensive and often require more maintenance. Specially treated coolant solution, rather than tap water, is necessary for a radiator cooling system because tap water can cause algae growth or scale (mineral buildup) on the gun's internal surfaces and cable assembly.

Over time water can leak from hoses, the gun neck, or head, requiring immediate repair to prevent weld discontinuities and gun failure. However, despite the additional cost, when welding on very thick plate that requires high deposition and good weld penetration, a water-cooled gun may be required.

Heavy-duty guns—both air- and water-cooled models—often have larger handles than their light-duty counterparts to accommodate large cables designed to carry high amperages. Such guns often use heavy-duty front-end consumables that can withstand high amperages and long arc-on times.

The goosenecks on these guns are often long as well, which puts more distance between the welding operator and the hot arc. Most goosenecks have aluminum armor that protects them from damage from high temperatures and day-to-day wear and tear. An optional heat shield protects the welding operator from the heat coming from the high amperage and longer arc-on time. The shield provides a barrier between the arc and the welding operator's hand. Adding a unicable cover also can help protect the power cable from a harsh environment.

Locking triggers help prevent operator fatigue when welding multiple passes or long, continuous joints. Other heavy-duty guns feature dual- or multischedule triggers that mount on the top or bottom of the gun, whichever the operator finds most comfortable.

In many cases, heavy-duty guns can be customized to meet the needs of the application and welder preference, including preferred handle styles, gooseneck length and angle, and unicable length.

Parting Thoughts

Just like any part of the welding process, GMAW guns play an important part in obtaining the quality and performance desired. Overusing a light-duty gun can result in poor performance, while using a heavy-duty gun without cause adds unnecessary cost. If a company has multiple power sources, one gun usually can be standardized to fit them through the addition of a feeder adapter. Doing so allows for one common gun to be used throughout the operation, lessening the need to inventory multiple styles of guns and consumables.

The goal is to accommodate both the amperage and duty cycle of the application in the best way possible. Moreover, proper welding gun selection can conserve resources and help welders achieve high productivity.

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The value chain: No longer just for task-related processes

2012-07-25T06:42:00.001-07:00

The value chain: No longer just for task-related processes

By Debbie Zmorenski • on September 13, 2010

Would you like to maximize the value impact of your talent management process? Consider conducting a value chain analysis of your organization's logistical activities for recruiting, hiring, retaining and growing your human capital.

Companies most often think of the value chain as it relates to manufacturing and technical processes. Seldom do companies think about their value chain when designing talent management processes. Yet, to maintain competitive advantage – especially during hard times – managing the human resources value chain is a critical component of an organization's future success.

The term "value chain" was first introduced by Michael Porter in the book "Competitive Advantage: Sustaining Superior Performance" (1985). Typically associated with manufacturing firms in the past, value creation and subsequently competitive advantage through value chain analysis and management provides an effective strategy for all businesses seeking streamlined, efficient operational processes that contribute to overall competitive strategy and, therefore, the bottom line of an organization.

Simply put, a value chain refers to the chain of activities within a firm's operations. Constructed at the business unit level, the value chain is a horizontal look at a firm with a process-product perspective versus the departmental view used for the budget. Products and services pass through all activities of the chain and ideally, at each activity, the product or service gains value. Porter's value chain model describes the components of the model as having primary activities and support activities, with the human resource management functions of recruiting, hiring, retaining and growing right-fit human resources as a key part of the support component.

Value chain analysis

Value chain analysis refers to the activities within and around the organization and relates them to an analysis of the organization's competitive strengths. Capturing the value generated along the chain is an approach popular with management strategists and can be looked at from an external and internal perspective. The external perspective, often referred to as the "value system" includes, in addition to internal factors, all external factors that impact the chain (e.g. vendors, vendors to the vendors, external corporate partners, outsource partners, etc.). A value chain analysis from the internal perspective looks only at the in-house processes and policies of the value chain, with consideration for how external factors may impact the internal activities.

Analyzing your talent management value chain

The purpose of analyzing the value chain of your talent management process is to identify how each business activity within the process contributes to your overall competitive strategy and where there may be efficiencies and cost savings to be gained within the process. An organization may create a cost advantage through value chain analysis by reducing the cost of the individual activities within the value chain or by reconfiguring the value chain.

Steps in the talent management value chain analysis:

Identify or clarify your overall competitive strategy: This may mean revisiting your vision and/or mission, or reiterating the firm's short-term and long-term goals, ensuring that everyone within all departments in the organization is on the same page.
Activity analysis: Identify each activity undertaken in the talent management process (recruiting, hiring, retaining and growing of human capital). This can be accomplished by conducting a brainstorming session or a business process review (BPR) with key individuals who are responsible for carrying out these activities and those who are impacted by these activities.
Value analysis: For each activity, assess the value that the activity brings to the process. Evaluate the pros and cons of making changes to the process. You must also consider how the changes may affect other departments within the organization and evaluate the overall impact of proposed changes.
Planning: Design and implement a strategic plan to reduce the costs of the activities within the talent management value chain or the cost to reconfigure the value chain.

As an example, we can apply these steps to the recruitment component of the talent management value chain. The first step is to ensure that the recruitment process supports the activity of attracting right-fit employees who will deliver on the competitive strategy of the organization. This may mean, for example, attracting people to the organization who have proven, exceptional customer service skills.

How the organization attracts right-fit employees is directly related to the recruiting activities. During the activity analysis, consideration must be given to the activities within all departments that are or should be involved in recruiting efforts (e.g., marketing, operations and communications).

Marketing may determine the types of ads to be placed, such as print ads for magazines and newspapers, electronic ads posted online, radio ads, etc. The marketing or communications departments may individually or collaboratively determine the verbiage and the aesthetics of the ads, ensuring that the culture of the organization is clearly represented to potential candidates. Operational departments may communicate their labor needs to HR, clearly outlining the particular requirements of the candidates, such as educational level, experience requirements, physical requirements, etc.

Further activity analysis involves dissecting each step within each activity. Below is a hypothetical example for a recruitment process utilizing print ads:

Designing the ad:
- Marketing Identifies pictures or artwork, if any, to be used
  - Solicit input from the hiring manager within the operations department
  - Solicit input from the general manager of the operations department
- Marketing and communications collaboratively identify verbiage to be used: key words or culture-related nomenclature
  - Solicit input from the hiring manager within the operations department
  - Solicit input from the general manager of the operations department
  - Submit for approval to the vice president of the marketing division
- Marketing and communications collaboratively determine the layout of the ad – the placement of verbiage in relationship to the artwork or pictures, prominence and placement of the company's logo
  - Solicit approval from the marketing director
  - Solicit approval from the communications director
Choosing the appropriate print media for the ad
- Magazines
- Newspapers
- Trade publications
Final proofing of the ad
- Submit to the operations manager for final approval
- Submit to the general manager of operations for final approval
- Submit to the marketing director for final approval
- Submit to the communications director for final approval
Determining the run time for the ad
- Submit to the finance manager for approval
- Submit to the general manager of the operations department for approval
Printing and distribution of the ad
- Send to the printer (outsourced)
- Printed materials returned to the marketing department
- Marketing distributes the final copy to the predetermined publications for printing

The value analysis involves analyzing the value impact of each of the activities identified during the activity analysis. In this example, the value analysis reveals cost savings opportunities by streamlining various activities. In the first step of designing the ad, it is not necessary to solicit input at each step from the hiring manager and the general manager of operations.

While it is critical to solicit input from the hiring manager at the beginning of the process to ensure that the recruitment ads will attract candidates with the skills, experience and education to fulfill all job requirements, it is not necessary to solicit input at every step in the process. Cost savings can be realized by streamlining the activities to solicit input from the hiring manager in the beginning and end of the process. Additionally, if the organization has a culture of trust, the general manager of operations can be eliminated entirely from the approval process, trusting the hiring manager to make good decisions regarding her recruitment needs.

There are also potential cost savings related to time efficiencies by allocating one place in the process, say the at the activity step of final ad proofing, for executive approvals, if it is determined that executives must approve ads before they go to print. Again, a culture of trust can reduce the list of approvals needed to send an ad to print. If the marketing manager and the communications manager are competent and right-fit for their jobs, is it necessary to send the ad to the marketing and communications director for final approval?

Measurements may be available that show certain print publications have not generated positive results in attracting right-fit candidates. Savings can be realized by determining which publications have yielded the best results and choosing only those publications with which to advertise.

An analysis of the printing activity may reveal cost saving opportunities if it is faster and less expensive to print the ad in-house. If the organization does not have in-house printing capabilities, the questions should be asked, "How long since we have sourced this function? How long since we have negotiated with the provider for a better price? Are there potentially other companies from which a better price can be negotiated?"

Once the value analysis of the value chain activities is complete, a secondary evaluation must be done before implementing changes. This evaluation process scrutinizes the cost to make changes, not only in monetary terms, but also in terms of the impact on other departments outside of the talent management value chain.

One thing to remember is that all internal value chains have a relational effect on all other value chain processes within the organization. The secondary evaluation may show that while cost savings can be realized within the talent management value chain process, making these changes may create hardships or additional monetary costs to the departments it impacts. By its very title, the word "chain" is a clue that all departments within an organization are interconnected and that for organizations to operate effectively as an entity, no decisions can be made in a vacuum.

The last step involves the development of the strategic plan to reduce the costs of the activities within the value chain or the cost to reconfigure the value chain once the cost savings opportunities have been identified. Minimally, the strategic plan must include:

Assurance that changes will deliver on the competitive strategies for the organization
Involvement of key players from all departments impacted by the changes
A realistic time line for implementing changes
A dispersal of responsibilities based on the talents and skills of the team
A measurement process for measuring the impact of changes made within the value chain process
A process for continuous improvement and ongoing management of the talent management value chain process

A value chain analysis is a strategic tool that, when conducted effectively, gives the organization the ability to identify how each business activity within an internal value chain contributes to the organization's competitive strategy, creating synergy between departments and making the strategy more systemic overall. The ability to identify and improve the logistical components of the talent management process allows an organization to leverage its top asset, the people within the organization. The overarching result is cost savings in the forms of process efficiency, reduced employee turnover, and excellent customer service leading to increased market share and customer loyalty.

I would be very interested in any ideas that you have for future topics. Please feel free to contact me by commenting below, sending an e-mail to debbiez@lsapartners.com or calling me at 407-497-0075. You may also want to visit our Web site at http://www.lsapartners.com for the latest and greatest on leadership and workforce development, operational effectiveness and other topics.

Source

Successful Management - 10 Simple People Skills

2012-07-25T06:37:00.001-07:00

Successful Management - 10 Simple People Skills

By Martin Haworth

Getting the best from your people is vital if you are to make the best progress in your business or organization. Much comes from the way you interact personally and here are just ten key actions to take to build great, fulfilling and productive relationships...

This might be a bit of a no-brainer for you.

If you have any role at all in managing people, you need to ensure that you develop great people skills.

By building rapport, you will develop ongoing, productive relationships with all of your people, which will give you an enormous return on the efforts you put in.

Here are ten things you can do, all of them easy, which will remarkably change the response you get from your people, the key asset you have in your business or organization:-

Just Have Conversations About anything! Talking to and more importantly, listening to your people regularly and informally is a great asset. It doesn't matter what it's about, Your understanding of them and their trust in you will magnify if you devote priority time to this each and every day.
Listen & Show you are Listening Take the time to really listen to each of your people, rather than just tell. If you truly hear, they will respond. Hearing is more - it is about what you do with the stuff you've listened to. And by using your face, your body language, eye contact and what you say (see 3 below), you will go a long way to showing that you are listening closely.
Ask Another Question Such a simple tactic. Ask secondary questions about what you've been told. Nothing, but nothing builds rapport and relationships like this. It shows that what they have been telling you is valuable, is interesting and builds their confidence. And you have been there to make that happen.
Support Your people need you to help them along the way. With your support, they will flower and grow. Support is what they hear from you - it works both ways.
Coach Don't get bogged down with technicalities. Coaching is about helping them see where they want to get to from where they are now. It's about exploring the possibilities - their possibilities, not yours and calling to action. Simple as that.
Clear Expectations By ensuring that all your people know exactly what you expect of them, they will tune in to delivering it. Confusion over performance is demoralizing and saps energy. Take the time to be clear.
Pay attention In any conversation with your people, take the time to give your full attention. Do your utmost to avoid being interrupted or distracted and truly value them for what they are saying to you - or the message you are giving them.
Show an Interest in Them These are real people and if you delve a little, it will show up. Having a real interest in who they are, their hopes and fears, their passions and what's important to them makes a big, big difference to how they perceive you. Get to know the name of their dog, if their dog is their most prized possession!
Follow Through During conversations you may offer actions that will be of value to them. Responses to what they have said to you. Make sure that you deliver these. Follow up and report back. Take actions you say you will. If you can't, tell them why.
Remember Conversations When you have subsequent conversations, recall something that was said previously and bring it up. This is hugely rewarding for them and lets them know that they said something of value.

Great managers really understand their people and work out ways to get the best out of every one of them.

Maximizing value from the most valuable asset you have in your business.

Your people.

Source

The Mythical 50% Resource

2012-07-25T06:36:00.001-07:00

The Mythical 50% Resource

By Dave Nielsen, PMP

Most managers of software development projects have had an encounter with a resource who is committed to their project some percentage of the time. The most common approach to splitting a resource between two tasks is to assign them 50% to both, although other percentages can occur. It's even been known to have a resource assigned to more than two tasks 50% of their time! Sharing a resource with another project or functional manager would not be a problem in a perfect world, but ours is never a perfect world and sharing a resource with another manager can present some challenges for the project manager. Here are some tips and tricks you can use to make the best of the situation.

When Sharing a Resource Won't Work

Never plan to employ a resource whose time is more than 100% accounted for. Your grade school math isn't wrong; there are still only 2 halves in a whole! It may seem like I'm stating the obvious here, but this situation does happen and the math gets explained away with excuses such as "Joe works a lot of overtime, so you can expect him to spend 20 hours a week on your project", or "Jane is very productive, she can easily deliver 50% more than any of the other programmers." Don't fall for it! Joe may work 20 hours of overtime one or two weeks, or even one or two months, but you can't expect him to keep up that pace throughout your project. Jane may be every bit as good as they say, but as the effort estimate for the work she will be performing is likely to come from her, you would have to factor in a 50% buffer to have a chance of meeting deadlines and that 50% buffer is going to be difficult to explain to your stakeholders. The chances of you getting one third of her time are also pretty remote.

Beware of situations where your partner manager is not in control of the amount of time the resource spends on their work. Help desk work is a perfect example. A developer who is scheduled to spend 50% of their time answering customer calls and resolving issues won't be able to guarantee they will only spend 4 hours of the day on that activity because they can't simply drop an issue which they are in the middle of resolving for a customer.

You have 3 choices when faced with a sharing arrangement that won't work: Negotiate a split to 100% of that resource's time, delay engaging the resource until you can get 100% of their time, or engage a resource to replace the one to be split.

When Sharing a Resource Will Work

There are times when a critical resource must be shared across multiple projects or operational activities. For example, when you need a resource for a task on the critical path and no other resource will do, you will have to compromise. Even when the task isn't on the critical path, postponing it may put it on the critical path before you identified an alternative solution.

Sharing a resource in an organisation which has experience with resource sharing, and with other managers who are experienced in sharing them, gives you more chance of success, but even if you're sharing a resource in an organisation unused to such arrangements and with other managers without experience in this area, there are tips and tricks you can use to improve your chances of success.

The key to successful resource sharing is teamwork between the sharing managers. To work successfully as a team, the managers must realise that the objectives of the projects or operational activities must be considered equally. If this weren't the case, the resource wouldn't be shared; they would go to the highest priority project or operational task. Teamwork here means that the sharing arrangement is planned between collaborating managers and a successful plan is one that supports both sets of objectives. Teamwork will also mean that the manager, or managers, you share resources with are now stakeholders in your project and should be treated accordingly in terms of project communications and any changes or risks that impact the shared resources.

Time Share

Time sharing is common practice now when customers share a vacation property and the same things that make this workable for vacation properties can facilitate sharing a resource. The "Time Share" approach plans the resource 100% on the activities of the first project. Once those activities have been completed the resource moves to the second project 100% of their time. This can be repeated as many times as necessary. Use common sense when determining the duration of the resource's stay on either project; the longer the resource spends on one task the more efficiently they will work. One day should be the absolute minimum block of time, with one week being the preferred minimum.

Compare project plans with the manager you plan to share the resource with to determine when the resource is needed on both projects. If the times at which you both require this resource clash, examine both plans to determine if activities can be juggled so that the resources activities can be sequenced in such a way that the resources time can be planned from start to end 100% on the first project, 100% on the second project, etc. until the resource can be released from both projects. Be flexible when planning this with your partner manager; you will both have to make some sacrifices in order to make this arrangement work. Working with an operational manager to achieve a time sharing arrangement will work the same way, but the operational manager may have more constraints which prevent them from re-scheduling activities.

Once you've reached an agreement on time sharing, update your project plan accordingly. MS Project provides calendars for individual resources. These calendars allow you to set aside time for the resource for individual activities such as training or vacations. Define the times the resource will be working on the partner project or operational activity as "unavailable." This will prevent you from accidentally scheduling your shared resource during a time when they are working on the other project. Remember that any schedule changes that involve the shared resource will have to be discussed with your partner manager. Acquisition and release dates become contracts between you and the other manager. You must honour your release date and expect the other manager to do likewise. Avoid any schedule slippages that impact the start or finish date of your shared resource's tasks. Slippages that can't be avoided need to be discussed with your partner manager. Your partner manager may be able to give you some extra time at end date, or utilise the resource after their start date if you give them enough notice. Remember that this arrangement works both ways so be prepared to accommodate your partner PM should the need arise.

The 50% Solution

There are situations where it is impossible to sequence the work of a shared resource, for example when a resource is responsible for ongoing support work which requires a few hours daily. The only possible solution in this case is to divide the resources time between your project and your partner manager's work.

The 50/50 split (or some other configuration) depends on a good working relationship with your partner manager and that manager's ability to control the resources time when they are working on their project or operational tasks. Define the terms of the sharing agreement with your partner. An arrangement which has the resource working on your project in the morning and the other project in the afternoon is the arrangement with the most chance of success so try to arrange the split so that the transfer happens at some natural break during the day - lunch break, or coffee break.

Terms of sharing should be formally documented, an e-mail or memo will do, but the document needs to capture the details of the arrangement, including start and stop dates, percentage split, how the resource's time is to be scheduled, and when the resource should be working on your project and when they should be working for the partner manager. This is your contract for sharing the resource. Hold your partner manager (and the resource) to the terms of this agreement and make sure you honor all your obligations.

Conclusions

There are some situations where resource sharing won't work and these must be worked around. If all else fails, escalate the issue to your sponsor explaining your need for the resource and why the sharing arrangement won't work for your project. In those situations where sharing can work, the easiest arrangement is the sequencing of the resource's activities between the two projects and when that can't be done, define the sharing arrangement in a formal document. Remember that there are 2 criteria for a workable sharing arrangement: the feasibility of the arrangement and the agreement between the two managers. Lastly, don't forget that when you share a resource with another manager that manager becomes a stakeholder in your project and you need to keep them in the loop.

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The tips and tricks described in this article are intended to help the project manager using the best practices promoted by the PMI. Project managers who are certified have already implemented those best practices. If you haven't been certified as a PMP (Project Management Professional) by the PMI and would like to learn more about certification, visit the three O Project Solutions website at: http://threeo.ca/pmpcertifications29.php. three O Project Solutions also offers a downloadable software based training tool that has prepared project managers around the world to pass their certification exams. For more information about this product, AceIt©, visit the three O website at:http://threeo.ca/featuress8.php
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Top 10 Risks of Offshore Outsourcing

2012-07-25T06:32:00.001-07:00

Top 10 Risks of Offshore Outsourcing

Dean Davison | December 9, 2003 12:00 AM PST

Offshore outsourcing is growing 20%-25% per annum, with little evidence of slowing. Indeed, while most enterprises experience initial resistance, most technical issues are readily resolved and geopolitical risk is deemed insignificant after careful evaluation. Even the current political fervor about jobs being moved offshore via outsourcing is not impacting the demand or strategy of IT organizations. Offshore outsourcing will continue to grow as a "labor arbitrage" model until 2008/09.

META Trend: During 2004/05, outsourcing will divide into commodity and transformational services. Infrastructure services will mirror grid-computing structures and develop consumption-based pricing (a.k.a., "utility services"). Through 2006/07, transformational services (e.g., application development maintenance and business process outsourcing) will segment along horizontal (function commonality) and vertical (specialized) business process/services outsourcing functions. Although vendors will attempt to bundle infrastructure with "value" services, clients will demand "line item" pricing by 2008/09.

Through 2004/05, IT organizations will outsource discrete projects/functions offshore (e.g., from application development projects to specific call center support). Growth will continue at 20%+. Offshore strategies by domestic vendors will shift business from large, integrated outsourcing contracts, but most IT organizations will still develop strategies that focus on pure-play offshore vendors. The top 10 risks of offshore outsourcing are as follows.

1. Cost-Reduction Expectations
The biggest risk with offshore outsourcing has nothing to do with outsourcing - it involves the expectations the internal organization has about how much the savings from offshore will be. Unfortunately, many executives assume that labor arbitrage will yield savings comparable to person-to-person comparison (e.g., a full-time equivalent in India will cost 40% less) without regard for the hidden costs and differences in operating models. In reality, most IT organizations save 15%-25% during the first year; by the third year, cost savings often reach 35%-40% as companies "go up the learning curve" for offshore outsourcing and modify operations to align to an offshore model.

2. Data Security/Protection
IT organizations evaluating any kind of outsourcing question whether vendors have sufficiently robust security practices and if vendors can meet the security requirements they have internally. While most IT organizations find offshore vendor security practices impressive (often exceeding internal practices), the risk of security breaks or intellectual property protection is inherently raised when working in international business. Privacy concerns must be completely addressed. Although these issues rarely pose major impediments to outsourcing, the requirements must be documented and the methods and integration with vendors defined.

3. Process Discipline (CMM)
The Capability Maturity Model (CMM) becomes an important measure of a company's readiness to adopt an offshore model. Offshore vendors require a standardized and repeatable model, which is why CMM Level 5 is a common characteristic. META Group observes that approximately 70% of IT organizations are at CMM Level 1 - creating a gap that is compensated for by additional vendor resources on-site (see Figure 1). Companies lacking internal process model maturity will undermine potential cost savings.

4. Loss of Business Knowledge
Most IT organizations have business knowledge that resides within the developers of applications. In some cases, this expertise may be a proprietary or competitive advantage. Companies must carefully assess business knowledge and determine if moving it either outside the company or to an offshore location will compromise company practices.

5. Vendor Failure to Deliver
A common oversight for IT organizations is a contingency plan - what happens if the vendor, all best intentions and contracts aside, simply fails to deliver. Although such failures are exceptions, they do occur, even with the superb quality methodologies of offshore vendors. When considering outsourcing, IT organizations should assess the implications of vendor failure (i.e., does failure have significant business performance implications?). High risk or exposure might deter the organization from outsourcing, it might shift the outsourcing strategy (e.g., from a single vendor to multiple vendors), or it might drive the company toward outsourcing (if the vendor has specific skills to reduce risks). The results of risk analysis vary between companies; it is the process of risk analysis that is paramount.

6. Scope Creep
There is no such thing as a fixed-price contract. All outsourcing contracts contain baselines and assumptions. If the actual work varies from estimates, the client will pay the difference. This simple fact has become a major obstacle for IT organizations that are surprised that the price was not "fixed" or that the vendor expects to be paid for incremental scope changes. Most projects change by 10%-15% during the development cycle.

7. Government Oversight/Regulation
Utilities, financial services institutions, and healthcare organizations, among others, face various degrees of government oversight. These IT organizations must ensure that the offshore vendor is sensitive to industry-specific requirements and the vendor's ability to: 1) comply with government regulations; and 2) provide sufficient "transparency" showing that it does comply and is thus accountable during audits. The issue of transparency is becoming more significant as requirements such as the USA PATRIOT Act and the Sarbanes-Oxley Act place greater burdens of accountability on all American corporations.

8. Culture
A representative example: although English is one official language in India, pronunciation and accents can vary tremendously. Many vendors put call center employees through accent training. In addition, cultural differences include religions, modes of dress, social activities, and even the way a question is answered. Most leading vendors have cultural education programs, but executives should not assume that cultural alignment will be insignificant or trivial.

9. Turnover of Key Personnel
Rapid growth among outsourcing vendors has created a dynamic labor market, especially in Bangalore, India. Key personnel are usually in demand for new, high-profile projects, or even at risk of being recruited by other offshore vendors. While offshore vendors will often quote overall turnover statistics that appear relatively low, the more important statistic to manage is the turnover of key personnel on an account. Common turnover levels are in the 15%-20% range, and creating contractual terms around those levels is a reasonable request. Indeed, META Group has seen recent contracts that place a "liability" on the vendor for any personnel that must be replaced. The impact of high turnover has an indirect cost on the IT organization, which must increase time spend on knowledge transfer and training new individuals.

10. Knowledge Transfer
The time and effort to transfer knowledge to the vendor is a cost rarely accounted for by IT organizations. Indeed, we observe that most IT organizations experience a 20% decline in productivity during the first year of an agreement, largely due to time spent transferring both technical and business knowledge to the vendor. Many offshore vendors are deploying video conferencing (avoiding travel) and classroom settings (creating one-to-many transfer) to improve the efficacy of knowledge transfer. In addition, employee turnover often places a burden on the IT organization to provide additional information for new team members.

Business Impact: Offshore outsourcing can reduce IT expenditures by 15%-25% within the first year. Longer term, process improvements often make great impacts on both cost savings and the quality of IT services delivered.

Bottom Line: As IT organizations consider the vast benefits and allure of offshore outsourcing, they must balance the risks and uncertainties with the potential for labor arbitrage.

META Group originally published this article on 14 November 2003.

The Perils Of Unskilled Labor

2012-07-25T06:30:00.001-07:00

The Perils Of Unskilled Labor

For years, American workers have grown increasingly angry over the exodus of U.S. jobs to fast-industrializing India. Think auto parts manufacturing, call centers, computer help desks, or software programming jobs. So it's not without a bit of irony that we note this week that employers on the Indian subcontinent -- many of whom have built their business models on offering lower-cost labor to Western companies -- are now experiencing labor shortages that are pushing their own wages up.

It seems that all the foreign demand for India's bargain-priced manufacturing and high-tech labor -- plus a boom in construction and consumer services jobs sparked by India's heady internal growth -- has left skilled workers at a premium across the subcontinent. Wages for some semi-skilled textile factory workers have jumped 10% this year, while supervisors' salaries have risen by 20%. And overall Indian salaries will rise 12.3% this year, Mercer Human Resource Consulting figures, more than double the nation's inflation rate.

While many U.S. workers might view this as a fitting comeuppance for Indian industry, that would be wrong for several reasons. The developed nations look increasingly to the Third World to provide them with ever-cheaper items to maintain high living standards. Call that the Wal-Mart (WMT ) effect. But too-rapid wage inflation in developing countries puts that symbiotic relationship at risk. Likewise, rising wages could fuel general inflation in India, slowing its economic growth and making Indian companies less able to buy high-value goods and services sold by First World companies. That eventually hurts Western workers as well.

The real problem for India isn't a lack of workers. In a nation where the population has tipped 1 billion, there's no shortage of warm bodies. Instead, India's ability to train new workers can't keep pace with its rapidly expanding economy's demand for manpower. For example, India's world-class elite universities boast fewer than 100,000 graduates each year. But its high schools graduate about 14 million students annually -- so nearly all go on to lesser universities or trade schools providing training beneath global standards.

The lesson here is that education, training, and development of intellectual infrastructure are every bit as important as low wages for today's global trading powers. (China recognized this early on; Mexico didn't.) Interestingly, that same message also offers hope for the more mature economies (and expensive workforces) of the U.S. and Europe. Continued investment in human capital may be their best hope to remain truly competitive in a world full of faster-growing, low-wage competitors. As India's current predicament shows, wages matter -- but skilled workers matter more.

Avoid the ‘Bloom and Doom’ Cycle

2012-07-25T06:28:00.003-07:00

Many Lean Six Sigma programs start out strong, but not all stay that way. Leaders must make special efforts to ensure their deployment ends up a success.

By Jason M. Morwick

Over the past decade, the success of Lean Six Sigma has been highly publicized. The widespread adoption of the process improvement methodology across many different business sectors is one indicator of success. However, little is written about companies that fail in their Six Sigma deployments, or at least scale back their support over time. For obvious reasons, companies are reluctant to air their dirty laundry, but the phenomenon is serious enough to warrant public discussion.

Although limited reliable data exists on companies that abandon, phase out or replace Six Sigma programs, only minimal digging is necessary to find anecdotal cases of deployments gone wrong. By having conversations with peers across various industries, sifting through the blogs of frustrated participants or reading the few negative reports on a company's Six Sigma experience, common warnings and patterns begin to emerge. The astute practitioner will notice that many companies that have had problems with their deployments face similar challenges and will see their programs move along the same rising and falling arc. This can be described as the "bloom and doom" curve, shown below.

The Six Sigma Deployment Bloom and Doom Curve

The Three Phases of Bloom and Doom

The Rise: This first phase of bloom and doom can be characterized by lots of excitement and initial support. Certification targets are published by organizational leaders (e.g. "X percent of the population must be Green Belt certified"). Ratios of Black Belts or Master Black Belts to employee base are standardized. Managers push to get their people certified. Employees are quick to realize how obtaining Six Sigma credentials will benefit their careers. Training classes are filled to capacity. Six Sigma can be found everywhere in the company. A myriad of projects are launched.

The Plateau: After certification targets are met, things start to slow down. Many of the company's employees have completed their obligatory certification projects and never complete another. Managers have been rewarded for reaching certification goals and only have to maintain current levels. Training classes begin to thin out because most employees are now trained.

The Decline: Finally, the Six Sigma program goes down a slippery slope. Managers give the program lip service at best or – at worst – completely disregard it. Leaders have already moved onto whatever initiative is the "next big thing." Employees don't attend training and initiate Six Sigma projects only if coerced. Training stats may not even be reported at this point. Projects don't follow the DMAIC roadmap, but are still labeled as Six Sigma projects. Project tollgates are nonexistent or done sporadically with limited attendance. Black Belts and Master Black Belts begin their mass exodus to other companies that are just starting Six Sigma or are still in the Rise phase. At this stage, Six Sigma exists at the company in name only.

The time period to go through all three phases can vary from organization to organization. The Rise can last from one to five years, the Plateau may be slightly shorter and the Decline can drag on indefinitely.

Five Ways to Defeat the Decline

This rise-and-fall pattern, however, is not inevitable. By following these five steps, practitioners can ensure that the path of their program will continue in a continuous upward arc.

1.    Select the right metrics. Remember that Six Sigma is not an end unto itself. The business results delivered through Six Sigma are what matters most, whether they are measured in hard or soft dollar savings, increased revenue, or improved customer satisfaction and loyalty. Beware when companies use metrics such as certification rates or the number of Belts as the primary indicators of success. Belt certification does not guarantee year-over-year business value. Once organizations have reached certification targets, there may be little incentive to continue their focus on Six Sigma without more relevant success metrics. The primary metrics to measure Six Sigma success should always be based on the business value returned to the company.

2.    Value the organization over the individual. Understandably, employees desire certification for many reasons, the most obvious of which is that certification will help them advance their careers. However, the importance of Green Belt or Black Belts diminishes over time if the only results they deliver are part of their certification projects. In terms of the number of Belts, more is not better if continued value is not delivered year after year. After all, what is the value of a Belt who does not complete a project? Zero. Six Sigma leaders should never be driven by an individual's desire for certification. Rather, organizational goals should be the focus, with individual certification as a positive byproduct of the process of achieving those goals.

3.    Select the right projects. Closely linked to the idea above, project selection is a key component to Six Sigma longevity. Projects should never be selected merely to get someone certified or to wrap DMAIC around a problem that is clearly not a Six Sigma project simply to gain visibility. Meaningful, impactful projects help keep momentum. Leaders should be very selective when applying Six Sigma. Additionally, project benefits should be validated by leaders outside the deployment, such as finance representatives, to avoid reporting inflated results that will eventually erode credibility.

4.    Build the right infrastructure. Who is ultimately accountable for the success of Six Sigma within an organization? Not the Belts. The organization's leadership determines success or failure. Too often, Belts are expected to carry a Six Sigma deployment. Instead, the organizational leaders that act as project sponsors or Champions should be the keystones to success. From communicating expectations and responsibilities to selecting projects and training leaders, management must provide the program with a strong foundation. Additionally, deployment leaders must evaluate foundational components of the business before implementing Six Sigma. For instance, does the organization exercise basic process management skills? Are processes documented and routinely maintained? Are metrics used to drive decision making? If not, leaders may have some more planning work to do before rolling out Six Sigma training and projects.

5.    Continually evolve the program. Despite what some will say, process improvement and quality are evolutionary, not revolutionary, endeavors. At the beginning of this decade, Lean was sometimes seen as a competing methodology to Six Sigma before people got smart and combined the two. The infusion of Lean tools and ideas helped to reinvigorate Six Sigma. Likewise, organizations should prevent Six Sigma from becoming stale. Six Sigma professionals can help by searching for ways to expand the skill sets of employees and keep the initiative fresh. Whether it involves the implementation of Design for Six Sigma (DFSS) to complement DMAIC, or the introduction of new tools, ideas or concepts, there is no reason to impede the growth of the continuous improvement body of knowledge.

Six Sigma practitioners all aim for continuous gains over time. The challenge is to maintain momentum after the initial surge and excitement wears off. The above actions, if taken at the beginning of the deployment, can create the right environment for sustainability. With these five elements in place, Six Sigma professionals can keep an eye on the warning signs to avoid the dreaded Plateau and prevent Decline.

About the Author: Jason M. Morwick is a Master Black Belt currently working for Cisco Systems Inc. He has a bachelor's degree from the U.S. Military Academy and an MBA. He can be reached at morwickj@aol.com .

Eight Keys To Successful DOE

2012-07-25T06:28:00.001-07:00

Eight Keys To
Successful DOE

DOE provides
an efficient
path to
improvement
for those who
know how to
use it.

by Mark J. Anderson and Shari L. Kraber

Quality managers who understand how to apply statistical tools for design of experiments (DOE) are better able to support use of DOE in their organizations. Ultimately, this can lead to breakthrough improvements in product quality and process efficiency.

DOE provides a cost-effective means for solving problems and developing new processes. The simplest, but most powerful, DOE tool is two-level factorial design, where each input variable is varied at high (+) and low (-) levels and the output observed for resultant changes. Statistics can then help determine which inputs have the greatest effect on outputs. For example, Figure 1 shows the results for a full two-level design on three factors affecting bearing life. Note the large increase at the rear upper right corner of the cube.

In this example, two factors, heat and cage, interact to produce an unexpected breakthrough in product quality. One-factor-at-a-time (OFAT) experimentation will never reveal such interactions. Two-level factorials, such as the one used in Figure 1, are much more efficient than OFAT because they make use of multivariate design. It's simply a matter of parallel processing (factorial design) vs. serial processing (OFAT). Furthermore, two-level factorials don't require you to run the full number of two-level combinations (2 ^{# of factors}), particularly when you get to five or more factors. By making use of fractional designs, the two-level approach can be extended to many factors without the cost of hundreds of runs. Therefore, these DOEs are ideal for screening many factors to identify the vital few that significantly affect your response.

Such improvements will obviously lead to increased market share and profit. So why don't more manufacturers use DOE? In some cases, it's simple ignorance, but even when companies provide proper training, experimenters resist DOE because it requires planning, discipline and the use of statistics. Fear of statistics is widespread, even among highly educated scientists and managers. Quality professionals can play a big role in helping their colleagues overcome their reluctance.

Using DOE successfully depends on understanding eight fundamental concepts. To illustrate these keys to success, we'll look at a typical example: reducing shrinkage of plastic parts from an injection molding process. The molding case will demonstrate the use of fractional two-level design.

1. Set good objectives

Before you can design an experiment, you must define its objective. The focus of the study may be to screen out the factors that aren't critical to the process, or it may be to optimize a few critical factors. A well-defined objective leads the experimenter to the correct DOE.

In the initial stage of process development or troubleshooting, the appropriate design choice is a fractional two-level factorial. This DOE screens a large number of factors in a minimal number of runs. However, if the process is already close to optimum conditions, then a response surface design may be most appropriate. It will explore a few factors over many levels.

If you don't identify the objectives of a study, you may pay the consequences--trying to study too many or too few factors, not measuring the correct responses, or arriving at conclusions that are already known.

Vague objectives lead to lost time and money, as well as frustration, for all involved. Identifying the objective upfront builds a common understanding of the project and expectations for the outcome.

In our case study of the injection molder, management wants to reduce variation in parts shrinkage. If the shrinkage can be stabilized, then mold dimensions can be adjusted so the parts can be made consistently.

The factors and levels to be studied are as shown in Table 1.

The experimenters have chosen a two-level factorial design with 32 runs. A full set of combinations would require 128 runs (2⁷), so this represents a 1/4th fraction.

2. Measure responses quantitatively

Many DOEs fail because their responses can't be measured quantitatively. A classic example is found with visual inspections for quality. Traditionally, process operators or inspectors use a qualitative system to determine whether a product passes or fails. At best, they may have boundary samples of minimally acceptable product. Although this system may be OK for production, it isn't precise enough for a good DOE. Pass/fail data can be used in DOE, but to do so is very inefficient. For example, if your process typically produces a 0.1 percent defect rate, you would expect to find five out of 5,000 parts defective. In order to execute a simple designed experiment that investigated three factors in eight experimental runs on such a process, you would need to utilize a minimum of 40,000 parts (8 x 5,000). This would assure getting enough defects to judge improvement, but at an exorbitant cost.

For the purposes of experimentation, a rating scale works well. Even crude scaling, from 1 to 5, is far better than using the simple pass/fail method. Define the scale by providing benchmarks in the form of defective units or pictures. Train three to five people to use the scale. During the experiment, each trained inspector should rate each unit. Some inspectors may tend to rate somewhat high or low, but this bias can be removed in the analysis via blocking (see Key 5, "Block out known sources of variation"). For a good DOE, the testing method must consistently produce reliable results.

In the case study on injection molding, the experimenters will measure percent shrinkage at a critical dimension on the part. This is a quantitative measurement requiring a great deal of precision. The short-term variation in parts can be dampened by measuring several and inputting the average. Other responses could be included, such as counts of blemishes and ratings of other imperfections in surface quality.

3. Replicate to dampen uncontrollable variation (noise)

The more times you replicate a given set of conditions, the more precisely you can estimate the response. Replication improves the chance of detecting a statistically significant effect (the signal) in the midst of natural process variation (the noise). In some processes, the noise drowns out the signal. Before you do a DOE, it helps to assess the signal-to-noise ratio. Then you can determine how many runs will be required for the DOE. You first must decide how much of a signal you want to be able to detect. Then you must estimate the noise. This can be determined from control charts, process capability studies, analysis of variance (ANOVA) from prior DOEs or a best guess based on experience.

The statisticians who developed two-level factorial designs incorporated "hidden" replication within the test matrixes. The level of replication is a direct function of the size of the DOE. You can use the data in Table 2 to determine how many two-level factorial runs you need in order to provide a 90-percent probability of detecting the desired signal. If you can't afford to do the necessary runs, then you must see what can be done to decrease noise. For example, Table 2 shows a minimum of 64 runs for a signal-to-noise ratio of 1. However, if you could cut the noise in half, the signal-to-noise ratio would double (to 2), thus reducing your runs from 64 to 16. If you can't reduce noise, then you must accept an increase in the detectable signal (the minimum effect that will be revealed by the DOE).

You can improve the power of the DOE by adding actual replicates where conditions are duplicated. You can't just get by with repeat samples or measurements. The entire process must be repeated from start to finish. If you do submit several samples from a given experimental run, enter the response as an average.

For our case study on injection molding, control charts reveal a standard deviation of 0.60. Management wants to detect an effect of magnitude 0.85. Therefore, the signal-to-noise ratio is approximately 1.4. The appropriate number of runs for this two-level factorial experiment is 32. We decide not to add further replicates due to time constraints, but several parts will be made from each run. The response for each run becomes the average shrinkage per part, thus dampening out variability in parts and the measurement itself.

4. Randomize the run order

The order in which you run the experiments should be randomized to avoid influence by uncontrolled variables such as tool wear, ambient temperature and changes in raw material. These changes, which often are time-related, can significantly influence the response. If you don't randomize the run order, the DOE may indicate factor effects that are really due to uncontrolled variables that just happened to change at the same time. For example, let's assume that you run an experiment to keep your copier from jamming so often during summer months. During the day-long DOE, you first run all the low levels of a setting (factor "A"), and then you run the high levels. Meanwhile, the humidity increases by 50 percent, creating a significant change in the response. (The physical properties of paper are very dependent on humidity.) In the analysis stage, factor A then appears to be significant, but it's actually the change in humidity that caused the effect. Randomization would have prevented this confusion.

The injection molders randomized the run order within each of several machines used for their DOE. The between-machine differences were blocked.

5. Block out known sources of variation

Blocking screens out noise caused by known sources of variation, such as raw material batch, shift changes or machine differences. By dividing your experimental runs into homogeneous blocks, and then arithmetically removing the difference, you increase the sensitivity of your DOE.

Don't block anything that you want to study. For example, if you want to measure the difference between two raw material suppliers, include them as factors to study in your DOE.

In the injection molding case study, management would like the experimenters to include all the machines in the DOE. There are four lines in the factory, which may differ slightly. The experimenters divide the DOE into four blocks of eight runs per production line. By running all lines simultaneously, the experiment will get done four times faster. However, in this case, where the DOE already is fractionated, there is a cost associated with breaking it up into blocks: The interaction of mold temperature and holding pressure can't be estimated due to aliasing. Aliasing is an unfortunate side effect of fractional or blocked factorials.

6. Know which effects (if any) will be aliased

An alias indicates that you've changed two or more things at the same time in the same way. Even unsophisticated experimenters know better, but aliasing is nevertheless a critical and often overlooked feature of Plackett-Burman, Taguchi designs or standard fractional factorials.

For example, if you try to study three factors in only four runs--a half-fraction--the main effects become aliased with the two-factor interactions. If you're lucky, only the main effects will be active, but more likely there will be at least one interaction. The bearings case (Figure 1) can be manipulated to show how dangerous it can be to run such a low-resolution fraction. Table 3 shows the full-factorial test matrix.

In this case, the interaction AB is very significant, so it's included in the matrix. (Note that this column is the product of columns A and B.) The half-fraction is represented by the shaded rows--the responses for the other runs have been struck out. Observe that in the highlighted area the pattern of the minuses (lows) and pluses (highs) for AB is identical to that of factor C. Put another way, C = C + AB, where the equal sign indicates aliasing. By going to the half-fraction, we don't know whether the effect is the result of C, AB or both.

Aliasing can be avoided by doing only full two-level factorials or high-resolution fractionals, which isn't practical. Plackett-Burman or Taguchi designs are often very low in resolution and therefore give very misleading results on specific effects. If you must deal with these nonstandard designs, always do a design evaluation to see what's aliased. Good DOE software will give you the necessary details, even if runs are deleted or levels changed. Then, if any effects are significant, you will know whether to rely on the results or do further verification.

The injection molding study is a fractional factorial design with mediocre resolution: Several two-factor interactions are aliased. A design evaluation provides the specifics: CE = CE + FG, CF = CF + EG, CG = CG + EF. If you evaluate the effects matrix for CE vs. FG, you will see a perfect correlation. The plus symbol in the alias relationship tells you that the calculated effect could be due to CE plus FG. If these or any of the other aliased interactions are significant, further work will be needed.

7. Do a sequential series of experiments

Designed experiments should be executed in an iterative manner so that information learned in one experiment can be applied to the next. For example, rather than running a very large experiment with many factors and using up the majority of your resources, consider starting with a smaller experiment and then building upon the results. A typical series of experiments consists of a screening design (fractional factorial) to identify the significant factors, a full factorial or response surface design to fully characterize or model the effects, followed up with confirmation runs to verify your results. If you make a mistake in the selection of your factor ranges or responses in a very large experiment, it can be very costly. Plan for a series of sequential experiments so you can remain flexible. A good guideline is not to invest more than 25 percent of your budget in the first DOE.

8. Always confirm critical findings

After all the effort that goes into planning, running and analyzing a designed experiment, it's very exciting to get the results of your work. There is a tendency to eagerly grab the results, rush out to production and say, "We have the answer!" Before doing that, you need to take the time to do a confirmation run and verify the outcome. Good software packages will provide you with a prediction interval to compare the results within some degree of confidence. Remember, in statistics you never deal with absolutes--there is always uncertainty in your recommendations. Be sure to double-check your results.

In the injection molding case, the results of the experiment revealed a significant interaction between booster pressure and moisture (CD). The interaction is not aliased with any other two-factor interactions, so it's a clear result. Shrinkage will be stabilized by keeping moisture low (D). This is known as a robust operating condition.

Contour graphs and 3-D projections help you visualize your response surface. To achieve robust operating conditions, look for flat areas in the response surface.

The 3-D surfaces are very impressive, but they're only as good as the data generated to create the predictive model. The results still must be confirmed. If you want to generate more sophisticated surfaces, you should follow up with response surface methods for optimization. These designs require at least three levels of each factor, so you should restrict your study to the vital few factors that survive the screening phase.

Promoting DOE

Design of experiments is a very powerful tool that can be utilized in all manufacturing industries. Quality managers who encourage DOE use will greatly increase their chances for making breakthrough improvements in product quality and process efficiency.

About the authors

Mark J. Anderson and Shari L. Kraber are consultants at Stat-Ease Inc. in Minneapolis. E-mail Anderson at manderson@qualitydigest.com .

Heat treating of aluminum and aluminum alloys

2012-07-25T06:26:00.001-07:00

Heat treating of aluminum and aluminum alloys

Abstract:

The general types of heat treatments applied to aluminum and its alloys are:

Preheating or homogenizing, to reduce chemical segregation of cast structures and to improve their workability
Annealing, to soften strain-hardened (work-hardened) and heat treated alloy structures, to relieve stresses, and to stabilize properties and dimensions
Solution heat treatments, to effect solid solution of alloying constituents and improve mechanical properties
Precipitation heat treatments, to provide hardening by precipitation of constituents from solid solution....

Heat treating processes for aluminum are precision processes. They must be carried out in furnaces properly designed and built to provide the thermal conditions required, and adequately equipped with control instruments to insure the desired continuity and uniformity of temperature-time cycles. To insure the final desired characteristics, process details must be established and controlled carefully for each type of product.

The general types of heat treatments applied to aluminum and its alloys are:

Preheating or homogenizing, to reduce chemical segregation of cast structures and to improve their workability
Annealing, to soften strain-hardened (work-hardened) and heat treated alloy structures, to relieve stresses, and to stabilize properties and dimensions
Solution heat treatments, to effect solid solution of alloying constituents and improve mechanical properties
Precipitation heat treatments, to provide hardening by precipitation of constituents from solid solution.

INGOT PREHEATING TREATMENTS (HOMOGENIZING)

The initial thermal operation applied to ingots prior to hot working is referred to as "ingot preheating", which has one or more purposes depending upon the alloy, product, and fabricating process involved. One of the principal objectives is improved workability. The microstructure of most alloys in the as-cast condition is quite heterogeneous. This is true for alloys that form solid solutions under equilibrium conditions, and even for relatively dilute alloys

ANNEALING

The distorted, dislocated structure resulting from cold working of aluminum is less stable than the strain-free, annealed state, to which it tends to revert. Lower-purity aluminum and commercial aluminum alloys undergo these structural changes only with annealing at elevated temperatures. Accompanying the structural reversion are changes in the various properties affected by cold working. These changes occur in several stages, according to temperature or time, and have led to the concept of different annealing mechanisms or processes.

Recovery. The reduction in the number of dislocations is greatest at the center of the grain fragments, producing a subgrain structure with networks or groups of dislocations at the subgrain boundaries. With increasing time and temperature of heating, polygonization becomes more nearly perfect and the subgrain size gradually increases. In this stage, many of the subgrains appear to have boundaries that are free of dislocation tangles and concentrations.

Recovery annealing is also accompanied by changes in other properties of cold worked aluminum. Complete recovery from the effects of cold working is obtained only with recrystallization.

Recrystallization is characterized by the gradual formation and appearance of a microscopically resolvable grain structure. The new structure is largely strain-free-there are few if any dislocations within the grains and no concentrations at the grain boundaries.

Grain Growth After Recrystallization. Heating after recrystallization may produce grain coarsening. This can take one of several forms.

PRECIPITATION HARDENING

General Principles of Precipitation Hardening. The heat treatable alloys contain amounts of soluble alloying elements that exceed the equilibrium solid solubility limit at room and moderately higher temperatures. The amount present may be less or more than the maximum that is soluble at the eutectic temperature.

Nature of Precipitates and Sources of Hardening. Intensive research during the past forty years has resulted in a progressive accumulation of knowledge concerning the atomic and crystallographic structural changes that occur in supersaturated solid solutions during precipitation and the mechanisms through which the structures form and alter alloy properties. In most precipitation-hardenable systems, a complex sequence of time-dependent and temperature-dependent changes is involved.

Kinetics of Solution and Precipitation. The relative rates at which solution and precipitation reactions occur with different solutes depend upon the respective diffusion rates, in addition to solubilities and alloy contents. Bulk diffusion coefficients for several of the commercially important alloying elements in aluminum were determined by various experimental methods.

Nucleation. The formation of zones can occur in an essentially continuous crystal lattice by a process of homogeneous nucleation. Recent investigations provide evidence that a critical vacancy concentration is required for this process and that a nucleation model involving vacancy-solute atom clusters is consistent with certain effects of solution temperature and quenching rate.

The nucleation of a new phase is greatly influenced by the existence of discontinuities in the lattice. Since in polycrystalline alloys grain boundaries, subgrain boundaries, dislocations, and interphase boundaries are locations of greater disorder and higher energy than the solid-solution matrix, they are preferred sites for nucleation of precipitates.

Quenching

Quenching is in many ways the most critical step in the sequence of heat treating operations. The objective of quenching is to preserve as nearly intact as possible the solid solution formed at the solution heat treating temperature, by rapidly cooling to some lower temperature, usually near room temperature.

Critical Temperature Range. The fundamentals involved in quenching precipitation-hardenable alloys are based on nucleation theory applied to diffusion-controlled solid state reactions. The effects of temperature on the kinetics of isothermal precipitation depend principally upon degree of supersaturation and rate of diffusion.

Quenching Medium. Water is not only the most widely used quenching medium but also the most effective. It is apparent that in immersion quenching, cooling rates can be reduced by increasing water temperature. Conditions that increase the stability of a vapor film around the part decrease the cooling rate; various additions to water that lower surface tension have the same effect.

Aging at Room Temperature (Natural Aging)

Most of the heat treatable alloys exhibit age hardening at room temperature after quenching, the rate and extent of such hardening varying from one alloy to another. No discernible microstructural changes accompany the room-temperature aging, since the hardening effects are attributable solely to the formation of zone structure within the solid solution.

Since the alloys are softer and more ductile immediately after quenching than after aging, straightening or forming operations may be performed more readily in the freshly quenched condition.

Precipitation Heat Treating (Artificial Aging)

The effects of precipitation on mechanical properties are greatly accelerated, and usually accentuated, by reheating the quenched material to about 100 to 200^oC. The effects are not entirely attributable to a changed reaction rate; as mentioned previously, the structural changes occurring at the elevated temperatures differ in fundamental ways from those occurring at room temperature. These differences are reflected in the mechanical characteristics and some physical properties. A characteristic feature of elevated-temperature aging effects on tensile properties is that the increase in yield strength is more pronounced than the increase in tensile strength. Also ductility, as measured by percentage elongation, decreases. Thus, an alloy in the T6 temper has higher strength but lower ductility than the same alloy in the T4 temper.

Precipitation Heat Treating Without Prior SoIution Heat Treatment

Certain alloys that are relatively insensitive to cooling rate during quenching can be either air cooled or water quenched directly from a final hot working operation. In either condition, these alloys will respond strongly to precipitation heat treatment.

Precipitation Heat Treating Cast Products

The mechanical properties of permanent mold, sand, and plaster castings of most alloys are greatly improved by solution heat treating, quenching, and precipitation heat treating, using practices analogous to those employed for wrought products.

The Advantages and Disadvantages of ERP

2012-07-25T06:25:00.001-07:00

The Advantages and Disadvantages of ERP

There are a number of powerful advantages to Enterprise Resource Planning. It has been used to solve a number of problems that have plagued large organizations in the past. At the same time, it is not without a number of disadvantages. Being able to weigh the two will allow a company to decide if this solution will properly meet their needs.

It should first be noted that companies that fail to utilize systems such as ERP may find themselves using various software packages that may not function well with each other. In the long run, this could make the company less efficient than it should be.

There are a number of processes that a company may need to integrate together. One of these processes is called design engineering. When a company is in the process of designing a product, the process of actually creating it is just as important as the end result. ERP can be useful in helping a company find the best design process. Another area where ERP can be useful is order tracking. When a company receives orders for a product, being able to properly track the orders can allow the company to get detailed information on their customers and marketing strategies. If different software packages are being used, this data may not be consistent.

Perhaps one of the most important advantages of ERP is its accounting applications. It can integrate the cost, profit, and revenue information of sales that are made, and it can be presented in a granular way. Enterprise Resource Planning can also be responsible for altering how a product is manufactured. A dating structure can be set up which can allow the company to be informed of when their product should be updated. This is important, because it will allow the company to keep better track of their products, and it can allow the products themselves to be produced with a higher level of quality. Another area where ERP can be an indispensable tool is the area of security. It can protect a company against crimes such as embezzlement or industrial espionage.

However, with all the advantages that ERP offers, there are a number of disadvantages as well. Perhaps one of the biggest disadvantages to this technology is the cost. At this time, only large corporations can truly take advantage of the benefits that are offered by this technology. This leaves most small and medium sized businesses in the dark. A number of studies have shown that the biggest challenges companies will face when trying to implement ERP deals with investment. The employees must be continually trained on how to use it, and it is also important for companies to make sure the integrity of the data is protected.

ERP has a number of limitations. The success of the system is fully dependent on how the workers utilize it. This means they must be properly trained, and a number of companies have attempted to save money by reducing the cost of training. Even if a company has enough money to implement ERP, they may not be able to successfully use it if they do not have enough money to train their workers on the process of using it. One of the biggest problems with ERP is that it is hard to customize. Very few companies can effectively use ERP right out of the box. It must be modified to suit their needs, and this process can be both expensive and tedious. Even when a company does begin changing the system, they are limited in what they can do.

Most ERP vendors will not allow the structure of the software to be altered. One advantage to ERP is that making the necessary changes to use it may actually make a company less competitive in the market. In addition to the costs involved with implemented ERP and training workers to use it, the ERP vendors may charge additional license fees, putting a strain on companies that do not have enough resources to pay for them. The technical support of ERP departments has been questioned, and a number of problems could arise due to security, since corporate representatives must give sensitive information to the tech support department.

Heading off health hazards : Guidelines for working injury free

2012-07-06T05:52:00.002-07:00

Heading off health hazards

Guidelines for working injury free

By Derek Baker

March 1, 2010

Each year more than 700,000 Americans injure their eyes at work equating to more than 2,000 eye injuries each day. About 90 percent of which could have been prevented if proper eye protection were used. Safe work practices, along with properly selected and worn PPE can help reduce many of these potential health hazards and help you to make sure you don't become a statistic.

Use caution when removing PPE or touching your face and eyes as these are the leading cause of foreign body eye injuries.

Welding, cutting, and grinding processes hold many potential health hazards. The most notable of these are injuries that result from eye and face impacts, arc radiation, inhalation of airborne contaminants, and noise. According to the organization Prevent Blindness of America, more than 700,000 Americans injure their eyes at work each year. That equates to more than 2,000 eye injuries each day, 90 percent of which could have been prevented if proper eye protection were used. Of the 700,000 eye injuries, 15,335 of them occurred while using welding equipment. According to the Bureau of Labor Statistics (BLS), 52,780 nonfatal facial injuries resulted in lost work time in 2004—36,680 of those were eye injuries.

Be Wise, Protect Your Eyes

Eye injuries can be classified into three categories:

Foreign body
Penetrating and blunt force
Arc welding radiation exposure

Foreign Bodies. Foreign body injuries are the most prevalent, but often are not related to welding, cutting, or grinding. Foreign body injuries usually occur postoperation, when grinding chips, metal pieces, or other small particles are brushed, rubbed, or fall into the eye as other tasks or work is being performed.

Even though you may have selected and worn the correct personal protective equipment (PPE), normal human behaviors such as removing headgear or safety equipment laden with metal shavings at the end of the day; wiping sweat from your brow; or simply scratching or rubbing your eyes, eyebrow, or forehead where metal shavings are ground into the fingers or resting on the skin of a sweaty face can cause foreign body injury. Of the 36,680 eye injuries stated previously, 35.6 percent of those were caused by rubbing.

Failing to wear safety glasses increases your chance of sustaining a blunt force eye injury.

Penetrating and Blunt Force. These eye injuries often result from a direct blow to the eye and eye area. PPE eyewear designed in accordance with ANSI Z87.1-2003 Occupational and Educational Personal Eye and Face Protection Devices standard are designed to cover, at a minimum, the eye socket area of the majority of the population. These design criteria are specified to reduce the chance of objects having a direct path to the eye. Of the 36,680 eye injuries, 19 percent were caused by being struck by a flying object.

Following safe work practices and selecting and wearing proper ANSI Z87 marked PPE are the best ways to help reduce overall eye and face injuries. As noted earlier, a spectacle's basic design intent is to protect the eye area from direct impact. Goggles are designed to cover the eye area, and some provide additional protection from dust, mist, and splashes. Face shields are designed to cover the eye area, but they also help protect the face against certain flying objects. It is important to note, however, that the ANSI Z87.1 standard requires the use of spectacles as primary eye protection under all face shields and welding helmets so that in the event the face shield or welding helmet is lifted up, the eyes are still covered by the spectacles.

Consider taking additional measures to help reduce your chance of eye injuries. Wear a head covering that can be removed easily at the end of the workday to cut down on the chance of metal chips and particles becoming entrapped in the hair or top of the head. Be careful when you remove these head coverings as well as when you shower to reduce potential fallout of particles.

Failing to wear safety glasses increases your chance of sustaining a blunt force eye injury.

PPE that incorporates powered and supplied-air options may be another means to help reduce eye injuries. These types of PPE often cover a large portion of your head and face and increase your comfort level by providing constant airflow across the head and face. This added comfort increases the likelihood of the product being worn, and worn correctly, further reducing potential injuries and helping enhance productivity.

Gloves also may reduce the chance of metal particles becoming ingrained in the skin, potentially reducing the rub-in effect.

Arc Radiation Exposure. Exposure to arc welding radiation is another form of eye injury. The three types of light emitted from a welding arc are ultraviolet (UV), visible, and infrared (IR). Visible light is the portion of light that can be seen by the eye easily. UV and IR light cannot be seen but are extremely dangerous and can cause painful and immediate eye injuries commonly known as "arc eye," which is essentially a sunburn of the cornea.

Multiple overexposures to UV and IR light can cause cumulative eye injuries that, if left unprotected, can ultimately lead to blindness and other permanent eye injuries. In addition to eye injuries, constant exposure to UV light may also damage the skin and contribute to skin cancer and other skin conditions. Using sunblock with an SPF of 50 or higher may also help protect you from overexposure to UV light.

According to the ANSI Z87.1 standard, you are required to wear primary eye protection under all welding helmets. Primary eye protection constitutes Z87 or Z87+ marked safety spectacles or goggles that will effectively block most of the UV light spectrum. Wearing safety spectacles under the welding helmet can significantly reduce eye damage from UV light even while the helmet is in the up position. Some specialty safety spectacles can provide additional protection against the IR component of light.

Overexposure to UV light causes "arc eye," or in other words a sunburn of the cornea.

A quality autodarkening welding helmet may help reduce eye injuries caused by arc radiation. Typically, welders who wear an autodarkening helmet leave the helmet in the down position more frequently than traditional passive welding helmets. This helps protect the eyes from stray and reflected arc radiation and also flying objects that contribute to foreign body and blunt force eye injuries. A quality autodarkening helmet can help reduce your exposure to arc radiation and other foreign body eye injuries, and may enhance productivity and comfort.

Inhaling Airborne Contaminants

Some welding, cutting, and grinding processes produce airborne contaminants that may require you to use a respiratory protection device. These contaminants can be in the form of particles or gases and vapors. Some examples of particles are metal fumes, dusts, and mists; examples of gases and vapors are ozone, fluorides, and shielding gases.

Hexavalent chromium (CrVI) is one of the potential particulate exposures regulated by OSHA. In February 2006, OSHA required employers to measure worker exposure to hexavalent chromium and establish control measures accordingly. OSHA reduced the permissible exposure limit (PEL) from a value of 52mg/m3 to a value of 5mg/m3 or a drop in exposure limits by more than an order of magnitude. OSHA has given employers until May 31, 2010, to place engineering controls in place, and if that is not feasible, to develop an effective respiratory protection program.

In most cases, an N95 particulate filter provides sufficient filtering capabilities. Depending on the results of worker air sampling and exposures, a half-facepiece respirator, such as a disposable filtering facepiece respirator with an assigned protection factor (APF) of 10, or a powered or supplied-air respiratory system providing an APF of 1,000, may be required.

Overexposure to IR light causes "arc eye," or in other words a sunburn of the cornea.

In addition to hexavalent chromium, other respiratory hazards may be present depending on the application or process. If air quality is in question, you should consult an industrial hygienist to perform a workplace assessment of your facility.

Noise Hazards

Welding, cutting, and grinding processes are often noisy and may require hearing conservation programs to mitigate noise hazards in these types of areas. There are five required elements of OSHA's hearing conservation standard, 29 CFR 1910.95:

Noise monitoring
Annual hearing testing
Hearing protection methods
Annual training
Recordkeeping

Environments that have a time weighted average (TWA) greater than 85 dBA require a hearing conservation program. As part of the program if the TWA is greater than 90 dBA, workers must wear hearing protection to reduce the TWA to less than 90 dBA. Additionally, employers must provide a suitable variety of hearing protection devices—two or more—to allow options for employees regarding fit and comfort.

The best hearing protectors are those that are worn correctly, have good fit, are worn consistently, and are comfortable. Many types of hearing protection devices (HPDs) are offered on the market today. HPDs include disposable foam earplugs, reusable molded earplugs, banded devices, and earmuffs with and without built-in communications.

When selecting an HPD, consider the performance or noise reduction and attenuation of the device. Also consider the effect the HPD has on communications and whether it will cause any adverse safety concerns while being worn. Next consider the comfort of the HPD throughout the wearing period. A device may be comfortable at first but become uncomfortable over a period of time. Next consider the ease of use: Is it easy to remove and reinsert into the ear, and is it compatible with other PPE used in the environment?

Last, consider the physical properties and ask how durable the device needs to be and the initial and long-term investment of the device. These basic questions will help you in selecting a suitable HPD.

Reg:aluminum beverage cans

2012-07-06T05:52:00.001-07:00

ALUMINUM/TIN CANS RECYCLING
Aluminum cans are the real success story of the recycling movement. By far, the most valuable component in the consumer waste stream, they enjoy the greatest public recognition as a recycled household item. Aluminum cans are often the economic backbone of municipal and private recycling programs. The price can fluctuate with the commodity price for new aluminum, but aluminum can scrap has always had a strong price in comparison to other recyclables.
Aluminum cans are collected in a variety of ways. In some countries, cans are returned through deposit schemes. With these systems you pay a deposit or fee when you purchase a full container. When the container is empty, you return it to a designated collection site and your fee is refunded. This collection method is very effective but the cost usually exceeds the recycling value for the containers. Buy back collection mechanisms is still very popular in many parts of the western hemisphere. People are offered money for aluminum cans that they collect and redeem at a recycling center or reverse vending machine. Most locations buy the cans by weight but some of the older systems pay for each can. Voluntary drop off locations are still in use in much of the EEC, and in more rural parts of the US. Many of these programs have been replaced by blue box programs, where a number of household recyclables are picked up at the curb and taken to large recycling facilities that sort and package the items for sale.

Recyclers can process aluminum cans in a number of ways. Small low volume processors will normally flatten cans and sell them to a nearby wholesaler. Larger operations will bale, densify or in some cases shred cans for shipment to aluminum consumers. The aluminum companies have defined specifications on how aluminum cans should be prepared.

How, exactly are the cans recycled ? After collection and processing the aluminum UBC ( Used Beverage Cans) are shipped by truck, railcar or sea container to smelting plants. The bales of cans are unloaded and tested for quality and moisture content. After inspection, the bales of cans are broken up in a shredder into small pieces. These shredded cans are then conveyed into a De-lacquering oven to remove the paint and residual moisture. The hot shredded aluminum is then passed over a small screen to remove and dirt and contaminants and fed directly into a reverbatory furnace. Heated to 1400 degrees Fahrenheit ( 650 Centigrade) the cans melt and blend in with the molten metal already in the furnace. A mixture of salt and KFl are added as a flux to help separate out any oxides (dross) that are skimmed off.

Molten aluminum is checked for proper chemistry and then tapped ( removed) from the furnace and poured into large molds that cast sheet ingots. These large rectangular ingots ( 20 to 40,000 lbs each) are allowed to cool and harden. When they are needed, the top and bottom surface of the sheet ingot ( alloy 3105) is milled to a smooth surface in a process called "Scalping". The scalped ingot is then passed between two giant steel rollers in a large rolling mill. The sheet is passed through a few more times until it is about 1/2 an inch (1.25 Cm) thick and maybe 1000 feet (300 meters)long. This long sheet is then annealed to soften it and passed to a series of rollers in a finishing mill where it acquires the necessary hardness and thickness. The edges are trimmed in a slitter and the coil is rolled up for shipment to a can manufacturer. The finished coil may be 2 miles (3 kilometers)long and made from over 1.2 million recycled cans.
If not properly recycled, an aluminum can will still be on the surface of the earth after 500 years. Aluminum recycling can reduce air pollution by 95%. It can save 90% to 95% of the energy required to manufacture aluminum from recycled aluminum cans than from aluminum core.

If each person recycles one aluminum can in each month, 1,750 to 3,500 gallons of gas can be saved
Tin cans can be processed in bales or into high density bricks for direct shipment into a steel mill. Material can be shipped via railcar, van trailer, dump trailer, flatbed or in walking floor trailers. Like aluminum, each mill has preferences on how they want material packaged and delivered. It takes a fairly substantial baling press to make a decent tin can bale. The product must be tight, especially if you are shipping on a flatbed truck. We currently purchase tin cans in the east, midwest and southern US and Canada. Let us know what you have available and we will contact you with a price.
Tin can bundles are relatively low in value and are seldom imported. The value to recyclers depends mostly on the amount of freight it takes to reach a steel mill. Recycling processors were paid between $30 and $80 a ton for baled tin cans picked up at their facilities in 1998. Fortunately, this material is abundant and easy to process so the handling costs are fairly low. Because they are magnetic, they are sorted from other recylables automatically with a magnetic conveyor belt. These belts usually feed the steel directly into an automatic baling press which produce mill quality 1000 to 2000 lb bales that are ready for shipment.

An interesting video for Aluminum Recycling

http://www.youtube.com/watch?v=AOpGhAdQFEY

Project Cost Management

2012-07-06T05:50:00.001-07:00

Project Cost Management

By Joseph Phillips

I'm not a huge fan of country music, but Lyle Lovett is one of my favourites. How can you not like Lyle Lovett? After all, he married Julia Roberts. (Ah, Julia Roberts, if you've read my articles before, you know how much I admire that smiling beauty. Sure, she snubbed Keifer, dumped Lyle, had a set of twins, and refuses to return my phone calls. Still, she is Julia Roberts.) Anyway, the point I'm trying to make is that I like Lyle Lovett's music: rhythm and blues, big band, good ol' country. In one of Lovett's songs, he croons, "Would you like a kiss?" She said, "Thank you, no. I'll take some M-O-N-E-Y." Project managers are like the girl in Lovett's song:

Management asks, "Would you like more time?" We respond, "Thank you, no. I'll take some M-O-N-E-Y."
Customers offer, "Would you like to reduce the scope?" We answer, "Thank you, no. I'll take some M-O-N-E-Y."
Sponsors demand a speedier schedule. We respond, "Thank you, no. I'll take some M-O-N-E-Y."

Get the point?

From IT to construction, most projects have to purchase materials: routers and cables, shingles and cement, and so on. We almost always must buy some things to complete the project work. Think back to your last project; didn't you have to buy something? A piece of software. A book. A large double-cheese and sausage pizza for your team. Someone, you or the organisation you work for, had to cough up the cash to buy that stuff.

Regardless of scope or schedule, projects need funds to complete the work. Technically, even projects that use only labour have funds attached to them; someone, somewhere is paying for that labour. What happens if you don't have the correct amount of funds to complete the project scope? Your project is doomed.

Got Your Money on Your Mind?

How do we know what a project will cost? We really don't, until the project is complete. I sound more like a car mechanic than a project manager, but the truth is, and this may sting just a little, we can't know the final project cost until the project is complete because we can't accurately predict the future.

What we can do is create an estimate. An estimate is more than pulling a random number out of the air, adding 20% for good measure, and then saying, "That'll work." A real estimate evolves as project details become available. This is progressive elaboration. Project estimates start out broad, and as the project deliverables come into focus we're able to more accurately define our estimates.

Each estimate should provide an acceptable range of variance, the conditions of the estimates, and any assumptions made by the estimate provider. For example, an estimate to build a new warehouse may state that the warehouse will cost $350,000, +/- 10%, is valid for 30 days, and assumes that the warehouse will be built in the month of June.

Notice the range of variance, the assumptions, and the stated work? A good estimate clearly defines what the project will accomplish, the assumptions made, how long the estimate is valid, and how much the project will cost based on current information. A good estimate presents to the stakeholder everything relevant to the proposed work, without holding back any secrets. If there's a disagreement in price, assumptions, or range variance, it's better to discuss this issue now rather than four months into the project execution.

There are three major estimate types that project managers should rely on:

The Ballpark Estimate is also known as the rough order of magnitude (ROM). A ROM estimate is based on high-level objectives, provides a bird's-eye view of the project deliverables, and has lots of wiggle room. Most ROM estimates, depending on the industry, have a range of variance from -25% all the way to +75%. Like I said, lots of wiggle room.
The project manager shouldn't invest too much time in creating these initial estimates, just as the customer shouldn't place too much confidence in the accuracy of the ROM estimate. Unfortunately for both parties, there's a consistent breakdown in expectations when it comes to ROM estimates. Typically the project manager blindly throws out the ROM estimate like a bride tossing her bouquet, and the customer clings to the ROM bouquet like the maid of honour at the same wedding. ROM estimates, regardless of your role in the project, are simply for eyeballing the project's initial perceived costs.
The Budget Estimate (or top-down estimate) is a bit more accurate. Formulated fairly early in the project's planning stage, the budget estimate is most often based on analogous estimating, taking budget lessons learned from a similar project and applying them to the current project. Do a little maths magic and we've got ourselves a budget estimate. Abra-cadaver!
With the budget estimate, we start at the top and work our way down into the project details. Like the ROM, this estimate should include conditions, a range of variance, and any assumptions that went into your calculations. A budget estimate is quick, but not very accurate. The range of variance on the budget estimate is from -10 percent to +25 percent.
The Definitive Estimate (or bottom-up estimate) is the most accurate of the estimate types, but takes the most time to create. The definitive estimate requires a work breakdown structure (WBS). A WBS is not a list of activities. (I know, everyone at your office says it is, but they're all wrong.) A WBS is a deliverables-oriented decomposition of the project scope. That's decomposition of the deliverables that your project will create for the customer, nouns, not verbs.

For example, suppose you need to create a network from scratch in your organisation's headquarters. Your WBS will stem from the project name HQ Network. Below HQ Network, you create a family tree of major deliverables: LAN, WAN, server room, workstations, and so on. Then you decompose these major deliverables into smaller deliverables.

Your WBS should use a code of accounts to number each deliverable in the WBS. For example, assume that the HQ Network is project number 427. The WAN section of this project might be 427.1, and the elements under the WAN deliverables would then be 427.1.1, 427.1.2, and so on. This code of accounts clarifies for all participants the deliverable that is being referenced, providing an accurate record for any element the project manager promises as part of the project completion. You don't have to use a code of accounts, but it's easy enough to implement, and can save time downstream.

You need a WBS in order to create the definitive estimate because you and/or your experts will account for the cost of each deliverable. In some organisations, that cost can include more than just the materials, it may take into account labour, consultants, team development, and so on. The point is that each deliverable in the WBS can have time and costs associated with it. Depending on the size of your project, you may want or need to create a WBS dictionary to take advantage of the code of accounts for each of the WBS elements: defining each element, the party responsible for the element, time and costs associated with each component, and other notes or relevant facts.

A WBS dictionary, coupled with the code of accounts, helps to prevent or resolve miscommunications, provide accurate references, and organise the project deliverables. Tied to the WBS dictionary are time, costs, and relevant info on each deliverable. Now you and Larry from Accounting can be best friends forever. You can move to any deliverable in the project and give an accurate estimate of what each thing will cost to implement.

A definitive estimate takes lots of time to create, but it's the most accurate estimate you can provide. You may know this as a bottom-up estimate because you start from zero (the bottom) and account for each freakin' thing the project will purchase, create, or deliver. The range of variance on a definitive estimate is relatively low: -5% to +10%. This makes sense because it's much easier to predict how much something will cost when you can see everything the project will create. How many projects have you been involved in where you can see everything the project will create from the word go? Probably not too many, or only projects that you've completed repeatedly and therefore know exactly what's expected. For example, an IT integrator may have a project template that defines all of the work to implement a prepackaged solution in any environment.

While definitive estimates are ideal for accuracy, they're not easy to create because so much effort has to go into the project before the project manager can create the definitive estimate. This requires education not just for you as project manager, but for your stakeholders, who need to understand that the only way a precise estimate can be created is to invest time in the project itself, by creating the WBS.

With any type of estimate, the project manager must provide the range of variance and an explanation of how the estimate was created. Without these explanations, the customer is led to believe that the price you've quoted, the price you've "promised," is the final price that the customer will see. And should the price tag change, there'll be hell to pay.

Got Your Mind on Your Money?

As the project moves toward completion, there will likely be a need to revise the project's price. If the project started with a ROM estimate, the original estimate could be wildly wrong. The customer who reads the ROM estimate should know that the final cost is likely to be much different from that estimate. No doubt the customer will be anxious to hear your more accurate definitive estimate.

Of course, from ROM to definitive, estimates can be just plain wrong. It's not fun to have to approach your sponsor, stakeholders, or customer with hat in hand and beg, plead, scrounge for more cash because your project estimate was way, way off. Poor planning is the major cause of poor estimates. Rushed estimates, bloated estimates, or estimates that are "low-balled" just to get the project moving are bound for budget reviews, unpleasant conversations, and project reassessments.

Sometimes, thankfully, it's not the project manager's fault when the estimate must change: The cost of materials has changed, the anticipated time to complete the project work was wrong, or the bases for decisions were faulty. In these instances, the project manager still has to communicate the variances, which isn't fun, but it's easier than taking the blame when that blame is all yours.

Poor estimates can also be the fault of the customer, stakeholders, or even the project sponsor. When the stakeholder is responsible, the increase in cost is usually tied to a change request. Contrary to public opinion, change requests are not good things. Ideally, when the customer and the project sponsor sign off on the scope statement, no changes should ever be made to that scope. Of course, errors and omissions, technological enhancements, and value-added changes all affect the scope's resistance to change.

If the customer demands new deliverables in the project scope, however, a price tag is usually associated with those demands. The monies needed to implement the change have to come from somewhere, and not your wallet. Even changes that replace current scope components may have a price; time and monies may already have been invested in these deliverables. In my opinion, change after the scope statement is a bad, bad thing.

We'll talk more about change management in a future article. For now, know this: When the project scope changes, the budget usually has to change as well. Changes generally cost something, and that means a budget increase.

IT and Project Cost Control

Do you ever feel like you're playing on the budget dartboard? The vendor's cost has increased. The historical information is flawed. Time estimates are incorrect. The project team is spread too thin. The bribe was lower than expected. Excuses, excuses, right?

IT suffers from a universal law: the first-time, first-use penalty. The concept of the first-time, first-use penalty is that it's next to impossible to accurately estimate the cost of something that has never been attempted. IT is so unique, so multifaceted, and has so many fronts that the constant movement of its variables creates a love-hate relationship for any organisation trying to create an IT cost estimate.

Consider any IT project, from replacing hardware to rolling out an entire new system, and I bet you've got a first-time, first-use scenario in there somewhere. Sure, that type of work may have been done before, but not in this project's specific environment. You've got different types of hardware, firmware, software, and don't forget users, banging up against your solutions. All of these factors are often ignored, dismissed, or assumed to be non-issues. Mistake! When it comes to cost and things that can affect cost, the project manager must consider the risk and ramifications of the first-time, first-use penalty. This universal law can spell disaster for any IT project. The longer a project manager goes without at least nodding in the direction of the first-time, first-use penalty, the bigger the pending fall.

Cost and the Project Manager

Project managers are in a tough spot: They're the liaison between the customer and the project team that will complete the customer's project. In most organisations, it's generally easier to get more time than money, and there's usually more concern about how much than how long. Project managers and their stakeholders need to go into any project with a common goal: Identify an affordable scope and a plan of how to achieve it. Too often, and maybe because of the subject matter itself, cost is ignored in project planning. For projects to be successful, someone has to foot the bill, and until the estimate is requested or provided, it's not a mystery, just a constant dread.

Cost management really is like a Lyle Lovett song: It can be painfully sad, honest, and focused on M-O-N-E-Y, without ever really saying that word.

Joseph Phillips is the author of five books on project management and is a PMI Project Management Professional, a CompTIA certified Project Professional, and a Certified Technical Trainer.

Types of Nondestructive Testing

2012-07-06T05:49:00.003-07:00

Types of Nondestructive Testing

Liquid Penetrate Testing (PT)

Liquid Penetrant Testing is sometimes called dye penetrant testing (DPI) or liquid penetrant inspection (LPI). One of the most cost effective ndt methods used to test non-ferrous materials. This method locates surface defects in nonporous materials when you apply a fluorescent or non-fluorescent dye penetrant to the surface. This method can detect cracks, fatigue cracks, forging and casting defects.

Magnetic Particle Inspection (MT)

Common ndt method that is capable of detecting surface and subsurface defects in ferrous materials. The method involves the induction of a magnetic field to or around the test specimen. If the material has a surface or near surface flaw it will create magnetic flux. These magnetic fluxes will attract small magnetic particles to the flaw area making it detectable. Also known as Magnetic Particle Inspection (MPI)

Radiographic Testing (RT)

This ndt inspection method uses wavelength electromagnetic radiation to penetrate various materials to detect flaws. This x-ray detection can be used on lead and steel to detected external and internal flaws but cannot be used on plastics. Radiation Safety is very important when using this testing method due to the possible exposure to strong gamma sources in remote sites.

Eddy Current Testing (ET)

Eddy current testing uses electromagnet induction in conductive materials to detect flaws. This method can detect very small flaws in or near the surface of the material. It is limited to conductive material and the surface must be accessible.

Ultrasonic Testing (UT)

Ultrasonic testing takes place when you send short ultrasonic pulse-wave into the material to detect internal flaws or identify different types of material. This method is also commonly used to determine the thickness of material. UT testing can be used on alloys, steel, concrete, wood and composites.

Visual Inspection Testing (VT)

Visual Inspection is the most common and readily available inspection. It is the process of eye fixations on a test specimen. Many times the inspector is trained to look for certain clues that might indicate defects or flaws. Most ndt inspections start with a visual inspection.

NDT Method Summary

2012-07-06T05:49:00.001-07:00

NDT Method Summary

No single NDT method will work for all flaw detection or measurement applications. Each of the methods has advantages and disadvantages when compared to other methods. The table below summarizes the scientific principles, common uses and the advantages and disadvantages for some of the most often used NDT methods.

Penetrant Testing	Magnetic Particle Testing	Ultrasonic Testing	Eddy Current Testing	Radiographic Testing

Scientific Principles
Penetrant solution is applied to the surface of a precleaned component. The liquid is pulled into surface-breaking defects by capillary action. Excess penetrant material is carefully cleaned from the surface. A developer is applied to pull the trapped penetrant back to the surface where it is spread out and forms an indication. The indication is much easier to see than the actual defect.	A magnetic field is established in a component made from ferromagnetic material. The magnetic lines of force travel through the material, and exit and reenter the material at the poles. Defects such as crack or voids cannot support as much flux, and force some of the flux outside of the part. Magnetic particles distributed over the component will be attracted to areas of flux leakage and produce a visible indication.	High frequency sound waves are sent into a material by use of a transducer. The sound waves travel through the material and are received by the same transducer or a second transducer. The amount of energy transmitted or received and the time the energy is received are analyzed to determine the presence of flaws. Changes in material thickness, and changes in material properties can also be measured.	Alternating electrical current is passed through a coil producing a magnetic field. When the coil is placed near a conductive material, the changing magnetic field induces current flow in the material. These currents travel in closed loops and are called eddy currents. Eddy currents produce their own magnetic field that can be measured and used to find flaws and characterize conductivity, permeability, and dimensional features.	X-rays are used to produce images of objects using film or other detector that is sensitive to radiation. The test object is placed between the radiation source and detector. The thickness and the density of the material that X-rays must penetrate affects the amount of radiation reaching the detector. This variation in radiation produces an image on the detector that often shows internal features of the test object.
Main Uses
Used to locate cracks, porosity, and other defects that break the surface of a material and have enough volume to trap and hold the penetrant material. Liquid penetrant testing is used to inspect large areas very efficiently and will work on most nonporous materials.	Used to inspect ferromagnetic materials (those that can be magnetized) for defects that result in a transition in the magnetic permeability of a material. Magnetic particle inspection can detect surface and near surface defects.	Used to locate surface and subsurface defects in many materials including metals, plastics, and wood. Ultrasonic inspection is also used to measure the thickness of materials and otherwise characterize properties of material based on sound velocity and attenuation measurements.	Used to detect surface and near-surface flaws in conductive materials, such as the metals. Eddy current inspection is also used to sort materials based on electrical conductivity and magnetic permeability, and measures the thickness of thin sheets of metal and nonconductive coatings such as paint.	Used to inspect almost any material for surface and subsurface defects. X-rays can also be used to locates and measures internal features, confirm the location of hidden parts in an assembly, and to measure thickness of materials.
Main Advantages
Large surface areas or large volumes of parts/materials can be inspected rapidly and at low cost. Parts with complex geometry are routinely inspected. Indications are produced directly on surface of the part providing a visual image of the discontinuity. Equipment investment is minimal.	Large surface areas of complex parts can be inspected rapidly. Can detect surface and subsurface flaws. Surface preparation is less critical than it is in penetrant inspection. Magnetic particle indications are produced directly on the surface of the part and form an image of the discontinuity. Equipment costs are relatively low.	Depth of penetration for flaw detection or measurement is superior to other methods. Only single sided access is required. Provides distance information. Minimum part preparation is required. Method can be used for much more than just flaw detection.	Detects surface and near surface defects. Test probe does not need to contact the part. Method can be used for more than flaw detection. Minimum part preparation is required.	Can be used to inspect virtually all materials. Detects surface and subsurface defects. Ability to inspect complex shapes and multi-layered structures without disassembly. Minimum part preparation is required.
Disadvantages
Detects only surface breaking defects. Surface preparation is critical as contaminants can mask defects. Requires a relatively smooth and nonporous surface. Post cleaning is necessary to remove chemicals. Requires multiple operations under controlled conditions. Chemical handling precautions are necessary (toxicity, fire, waste).	Only ferromagnetic materials can be inspected. Proper alignment of magnetic field and defect is critical. Large currents are needed for very large parts. Requires relatively smooth surface. Paint or other nonmagnetic coverings adversely affect sensitivity. Demagnetization and post cleaning is usually necessary.	Surface must be accessible to probe and couplant. Skill and training required is more extensive than other technique. Surface finish and roughness can interfere with inspection. Thin parts may be difficult to inspect. Linear defects oriented parallel to the sound beam can go undetected. Reference standards are often needed.	Only conductive materials can be inspected. Ferromagnetic materials require special treatment to address magnetic permeability. Depth of penetration is limited. Flaws that lie parallel to the inspection probe coil winding direction can go undetected. Skill and training required is more extensive than other techniques. Surface finish and roughness may interfere. Reference standards are needed for setup.	Extensive operator training and skill required. Access to both sides of the structure is usually required. Orientation of the radiation beam to non-volumetric defects is critical. Field inspection of thick section can be time consuming. Relatively expensive equipment investment is required. Possible radiation hazard for personnel.
Penetrant Testing	Magnetic Particle Testing	Ultrasonic Testing	Eddy Current Testing	Radiographic Testing

Theory of Constraints — The Goal

2012-07-06T05:48:00.001-07:00

Theory of Constraints — The Goal

Whether you are a student of science, a project manager or working in manufacturing organizations or IT – the Theory of Constraints has its application in every field. The underlying business ideas of increasing efficiency/effectiveness and the challenges most managers feel in balancing personal and work commitments are timeless.

Theory of Constraints (TOC) is an overall management philosophy introduced by Dr. Eliyahu M. Goldratt in his 1984 book titled The Goal, that is geared to help organizations continually achieve their goal. The title comes from the contention that any manageable system is limited in achieving more of its goal by a very small number of constraints, and that there is always at least one constraint. The TOC process seeks to identify the constraint and restructure the rest of the organization around it, through the use of the Five Focusing Steps.

Key assumption

The underlying assumption of Theory of Constraints is that organizations can be measured and controlled by variations on three measures: throughput, operating expense, and inventory. Throughput is money (or goal units) generated through sales. Inventory is money the system invests in order to sell its goods and services. Operating expense is all the money the system spends in order to turn inventory into throughput.

The five focusing steps

Theory of Constraints is based on the premise that the rate of goal achievement is limited by at least one constraining process. Only by increasing flow through the constraint can overall throughput be increased.

Assuming the goal of the organization has been articulated (e.g., "Make money now and in the future") the steps are:

1. Identify the constraint (the resource or policy that prevents the organization from obtaining more of the goal)
2. Decide how to exploit the constraint (make sure the constraint's time is not wasted doing things that it should not do)
3. Subordinate all other processes to above decision (align the whole system or organization to support the decision made above)
4. Elevate the constraint (if required or possible, permanently increase capacity of the constraint; "buy more")
5. If, as a result of these steps, the constraint has moved, return to Step 1. Don't let inertia become the constraint.

The five focusing steps aim to ensure ongoing improvement efforts are centered around the organization's constraints. In the TOC literature, this is referred to as the "Process of Ongoing Improvement" (POOGI).

These focusing steps are the key steps to developing the specific applications mentioned below.

Constraints

A constraint is anything that prevents the system from achieving more of its goal. There are many ways that constraints can show up, but a core principle within TOC is that there are not tens or hundreds of constraints. There is at least one and at most a few in any given system. Constraints can be internal or external to the system. An internal constraint is in evidence when the market demands more from the system than it can deliver. If this is the case, then the focus of the organization should be on discovering that constraint and following the five focusing steps to open it up (and potentially remove it). An external constraint exists when the system can produce more than the market will bear. If this is the case, then the organization should focus on mechanisms to create more demand for its products or services.

Types of (internal) constraints

* Equipment: The way equipment is currently used limits the ability of the system to produce more salable goods / services.
* People: Lack of skilled people limits the system.
* Policy: A written or unwritten policy prevents the system from making more.

The concept of the constraint in Theory of Constraints differs from the constraint that shows up in mathematical optimization. In TOC, the constraint is used as a focusing mechanism for management of the system. In optimization, the constraint is written into the mathematical expressions to limit the scope of the solution (X can be no greater than 5).

Please note: Organizations have many problems with equipment, people, policies, etc. But the constraint is the thing that is preventing the organization from getting more Throughput (typically, sales).

Buffers

Buffers are used throughout Theory of Constraints. They appear as part of the EXPLOIT and SUBORDINATE steps of the five focusing steps. Buffers are placed before the key constraint, thus ensuring that the constraint is never starved. Buffers used in this way protect the constraint and should allow for normal variation of processing time and the occasional upset (Murphy) before the constraint.

Buffers can be a bank of physical objects before a work center, waiting to be processed by that work center. Buffers can also be represented by time, as in the time before work reaches the constraint. There should always be enough (but not excessive) work in the time queue before the constraint.

Buffers are not the small queue of work that sits before every work center in a Kanban system. The assumption in Theory of Constraints is that with one constraint in the system, all other parts of the system have sufficient capacity to keep up with the work at the constraint. In a balanced line, as dictated by Kanban, when one work center goes down, then the entire system must wait until that work center is restored. In a TOC system, the only situation where work is in danger is if the constraint is unable to process (either due to malfunction, sickness or a "hole" in the buffer).

Plant types

There are four primary types of plants in the TOC lexicon. Draw the flow of material from the bottom of a page to the top, and you get the four types. They specify the general flow of materials through a system, and they provide some hints about where to look for typical problems. The four types can be combined in many ways in larger facilities.

* I-Plant: Material flows in a sequence, such as in an assembly line. The primary work is done in a straight sequence of events (one-to-one). The constraint is the slowest operation.
* A-Plant: The general flow of material is many-to-one, such as in a plant where many sub-assemblies converge for a final assembly. The primary problem in A-plants is in synchronizing the converging lines so that each supplies the final assembly point at the right time.
* V-Plant: The general flow of material is one-to-many, such as a plant that takes one raw material and can make many final products. Classic examples are meat rendering plants or a steel manufacturer. The primary problem in V-plants is "robbing" where one operation (A) immediately after a diverging point "steals" materials meant for the other operation (B). Once the material has been processed by A, it cannot come back and be run through B without significant rework.
* T-Plant: The general flow is that of an I-Plant (or has multiple lines), which then splits into many assemblies (many-to-many). Most manufactured parts are used in multiple assemblies and nearly all assemblies use multiple parts. Customized devices, such as computers, are good examples. T-plants suffer from both synchronization problems of A-plants (parts aren't all available for an assembly) and the robbing problems of V-plants (one assembly steals parts that could have been used in another).

For non-material systems, one can draw the flow of work or the flow of processes and arrive at similar basic structures. A project, for example is an A-shaped sequence of work, culminating in a delivered project.

Outsourcing: Pros and Cons

2012-07-05T22:39:00.001-07:00

Outsourcing: Pros and Cons

Unlike the popular belief that outsourcing is a recent phenomenon, it actually has been in existence as long time. To understand the growing debate on outsourcing, it is pertinent to understand the pros and cons of outsourcing.

PRLog (Press Release) – Feb 11, 2009 – Outsourcing refers to the process wherein a business contracts with a third party service provider to provide services that might otherwise be performed by in-house employees of the business.
Unlike the popular belief that outsourcing is a recent phenomenon, it actually has been in existence as long as work specialization has existed. In fact, companies have been known to have used outsourcing in some form or the other since a long long time. Typically, companies have been known to outsource those functions that are considered non-core to the business or such functions which needed specialized skills unavailable in the open market.
Of late, outsourcing has been attracting a lot of debates. And the main reason for the ongoing debate is the emergence of service providers from various countries trying to provide services in foreign locations. To understand the growing debate on outsourcing, it is pertinent to understand the pros and cons of outsourcing.

The main advantages for business to opt for outsourcing are:
1. Cost Savings:- The costs associated with an in-house employee is always higher than the cost of an outside service provider and this is the primary reason for most of businesses to opt for outsourcing non-core functions.

2. Quality services:- Since most of the third party service providers excel at the services they provide, businesses are guaranteed of better quality than an in-house employee would give. Additionally, any service provider will always look to give the best of services since their reputation is at stake.

3. Access to specialized skills:- Any third party service provider will be expert at the service that it provides. In fact, to beat competition, it would have to keep honing the skills of its employees. Also, the service provider would build up specialized skills in it's niche area of operation. By outsourcing to such a service provider, business gets access to such specialized skills, which may be of use in some other field of operation of the business.

4. Contractual Obligation:- The liability of a service provider is higher than that of an in-house employee. This makes working with them a safer bet for businesses.

5. Staffing issues:- By outsourcing a non-core function, a business avoids all the headache associated with recruiting and hiring staff for such non-core function.

6. Risk Mitigation:- Many a times, non-core functions may become critical and would need skilled intervention, which the business may be lacking. At such times, if the same function is outsourced and becomes critical in the hands of the service provider, because of the talent pool available at the service provider's end and because of all the experiences it would have gained by way of servicing other clients, it would be in a much better position to counter any kind of risks.

7. Capacity Management:- There may be times when the non-core function may need additional hands to meet deadline. In such times, it would become difficult for an in-house employee to tackle the pressure. However, if the function is outsourced, the headache of meeting the deadline is of the service provider. Besides, since the service provider would have a significantly large talent pool at it's disposal, it can easily tide over such issues.

Those are some of the benefits associated with outsourcing. Let's now examine the flip side of outsourcing.

1. Linguistic barriers:- When a function that needs handling of calls is outsourced to a foreign location and the first language of that nation is different from the nation which outsources the function, it may lead to low quality call handling. This concern is evidently higher in call centre functions that are off shored. People find the the linguistic features such as accent, word use and phrases that might be very different and hence in-understandable.

2. Social Responsibility:- When off shoring is resorted to, which means outsourcing of a process to a foreign location, it results in reduction of employment avenues in the nation from where the function is outsourced. This goes against the social behavior of the business outsourcing the process.

3. Company knowledge:- An in-house employee will always have a better understanding of the nuances of a function since he/she would always have a better knowledge of the company and its business as compared to a third party.

4. Staff Turnover:- Many people debate that quality of a service provider is as good as its people and as and when there is a staff turnover, the quality of services will definitely suffer. In outsourcing processes, the jobs are highly monotonous and this makes people loathe the job after a while. This is a big factor contributing to higher turnover.

So, what do businesses do? Do they outsource or not? Is there anything that contradicts the negative points raised against outsourcing? The answer is "YES".
Let's go by the negative points one by one.

1. Linguistic barriers:- It is correct to say that linguistic barriers do pose a threat. However, there are number of countries which actually promote their people to learn foreign languages which help outsourcing processes a lot. One of these countries is India, where, there are numerous institutions that excel in teaching foreign languages. In fact, all the call centres in India have compulsory accent training for the agents before they go "live".

2. Social Responsibility:- It is true that off shoring of processes result in growth of unemployment in the country from where the processes are being outsourced. However, that's only one part of the story! Outsourcing results in a higher profitability for the businesses which are then ploughed back into the economy. This definitely has far better impact than the negative impact of growth in unemployment. In fact the negative aspect is broadly nullified by the positive impact of profit getting ploughed inside the economy.

3.Company Knowledge:- It's true that an employee would have a better knowledge of the business. However, that knowledge is not built overtime. Any service provider can build the same kind of knowledge provided there is a structured knowledge transfer from the business to the service provider.

4. Staff Turnover:- Staff turnover is something that even a business has to handle with in-house employee. This is something which is a common problem and hence cannot be used against outsourcing

Think before you integrate (robotic welding)

2012-07-05T22:37:00.003-07:00

Think before you integrate (robotic welding)

8 common mistakes and how to prevent them

By Bob Rochelle

March 1, 2010

Implementing robotic welding systems for the first time is generally a successful endeavor. However, potential pitfalls and common mistakes can lead to performance issues and increase operational costs. Making yourself aware of these mistakes and the measures you should take to prevent them will contribute to a pleasant transition from labor-intensive, manual processes to the lower-cost, higher-quality automated ones in use today and into the future.

Before taking the plunge with robotic welding, stop and consider these common mistakes so your experience is a successful one

The number of manufacturers investigating the benefits of flexible automation or robotic-based systems has rapidly increased in their quest to lower production costs and produce higher-quality products. Implementing robotic welding systems for the first time is generally a successful endeavor. However, potential pitfalls and common mistakes can lead to performance issues and increase operational costs.

Making yourself aware of these mistakes and the measures you should take to prevent them will contribute to a pleasant transition from labor-intensive, manual processes to the lower-cost, higher-quality automated ones in use today and into the future.

Mistake No. 1: Underestimating What You Need

The two most common mechanical ratings for industrial robots arepayload and reach. Payload is the maximum weight allowed, and reach refers to the range of motion for a robotic arm.

In welding applications, the payload is not really a concern because the torch, mounting brackets, and the mechanical breakaway mounted at the end of the arm are very light.

Therefore, when you're selecting a welding robot, you must give serious consideration to its reach. The welding robot must have a range of motion large enough to reach all the weld joints and to articulate the torch into postures to weld those joints successfully. Welding robots typically are sized based on existing production specifications.

However, it's wise to consider potential changes in the part you are welding. Will it get larger? Or is it possible that you could be welding other parts on your robotic welder that may require a larger reach or heavier payload in the future? Keep in mind that the cost to purchase a robot with a large reach now may require, say, a $10,000 investment. But buying a smaller robot for $40,000 today and then having to replace it with a larger or heavier one tomorrow for, say, $50,000 doesn't make sense. And this is just the cost of the robot and does not include any costs for modifying the system to accept the larger model.

During your decision process, consider purchasing a larger robot than you need right now; you might need it down the road.

Mistake No. 2: Ignoring Peripheral Equipment

Robot technology is a mystery to new users because they are unfamiliar with it, yet the robot is not the most crucial item in the overall system design. The single most important item in the robot-based manufacturing system is the end-of-arm tooling.

Robot tooling is the mechanism mounted to the robot that actually performs the work in your system. Examples of tooling include mechanical grippers, welding torches, vacuum grippers, grinding wheels, paint sprayers, sealant dispensers, and ultrasonic horns. The robot will still move as it is programmed even if tooling performs unreliably or incorrectly, but the system will not perform as designed. As a result, your manufacturing process will suffer and you'll produce unacceptable parts.

The end-of-arm tooling or process-specific peripheral equipment is the key to a successful robotic-based system—not the robot itself—so concentrate on that.

Mistake No. 3: Failing to Plan for Disaster

Disasters do not happen in a typical robotic installation, but problems can arise that may prove detrimental to your manufacturing process. Therefore, it is imperative that you identify these issues and put a plan in place to prevent them in your automated system design.

What happens if a molten metal casting drops, a chemical spills, or a box bottom opens and its contents spill? To prevent these and other problems adequately, you may have to include items like part diverters on conveyors to maintain movement in the event of a system malfunction. You may have to employ a manual workstation as a backup; use sensors to positively verify location, action, and part integrity; provide a means to verify that the robot program selected is consistent with the fixture in place and the actual part present; and evaluate the effects of hazardous materials or conditions. Robotic systems will operate reliably and safely if all potential problems that could lead to disasters are evaluated and solutions implemented during system design and operational planning.

Mistake No. 4: Believing Robots Are Too Complicated

Robots have evolved into simple devices considering the complexity of hard automation systems. In most cases, the robot is the most reliable component in today's automated systems. Industrial robots now have a mean-time-to-failure rating that approaches 100,000 hours of operation and routine maintenance intervals specified near 10,000 hours of operation. Along with this reliability rating, typical service procedures and part replacements often require mere minutes to perform. As a result, robots are not the most complicated mechanism in automated manufacturing.

Mistake No. 5: Eliminating Crucial Weld Personnel

One of the compelling reasons to automate with robots is to utilize them for routine or repetitive tasks, allowing shops to reduce labor costs by reducing head count. In welding, the robot guides the torch while the robot controller or welding power supply controls the weld process. Due to the simplicity of this system, it is quite common to use a "parts loader" instead of a trained welder as the robotic welding system operator, which reduces the labor cost in this production cell.

But welding is a process, regardless of whether it is manual or automated. Robotic welding systems require the expertise of a trained welder to maintain process integrity and to troubleshoot welding-related issues. A trained welder is as crucial in robotic welding as he is in any other welding process.

Mistake No. 6: Using Cost as the Deciding Factor

When you make the decision to automate your welding applications, the initial cost and the return on investment (ROI) calculations are critical. It's important to understand that the cost is not the only thing you need to consider. Many of today's robotic welding systems yield an ROI within several months, so selecting the least expensive system over one that is more expensive will add only a few weeks to the ROI, but at what hidden costs?

Be sure to check that the system you are interested in has all the components included that comprise a successful system during installation and start-up. Be on the lookout for critical components that might be missing, as these items generally cost more over the life of the system in rejected parts, system downtime, or lack of process integrity.

Mistake No. 7: Expecting the Robot to Do Too Much or Too Little

An industrial robot works in conditions similar to those a blind, one-armed man does while performing the same task. For the process to be successful, the parts must be made to a quality specification and must be repeatable. Tooling and parts locators or fixtures must provide a repeatable means for the robot to positively locate and present parts for processing.

Robot systems do not tolerate randomness. Whereas humans can see imperfections, make quick decisions, and adjust behaviors to adapt to a particular situation, robots cannot. Expecting the robot alone to assume such responsibilities is expecting it to do too much. Likewise, maintaining advanced manual operations along with a robot system or operating your robot system below capacity with a duty cycle way below capability may be expecting it to do too little.

Mistake No. 8: Failing to Consider Robotic Welding Technology in Your Shop

Robotic welding systems are now a mature product and have become a key ingredient in the modern manufacturing environment. The robot itself is a commodity item, especially in the welding and fabrication industries. It may not be the right answer for your automation needs, but with recent advancements in reliability, simplicity of operation and programming, ease of path modification, standard routines, and vision-based processes, robotic technology deserves consideration in your shop.

Hazard Identification Tool (HIT)

2012-07-05T22:37:00.001-07:00

Hazard Identification Tool (HIT)

Natural disasters often have secondary impacts, including damage to infrastructure and industrial installations. These so-called environmental emergencies may pose a threat to the health, security and welfare of the affected population and the emergency responders. Too often, these risks are neglected, resulting in preventable deaths and injuries. It is therefore essential that information on the location of the hazardous facilities and the potential impacts is made available to relevant authorities and emergency responders at a very early stage of the disaster response or even prior to the onset of a disaster.

The Hazard Identification Tool (HIT) has been developed to assist in the desk research based identification of potentially hazardous facilities. The HIT User Guide gives information on the HIT objective and methodology and provides the user with step-by-step guidance on how to apply the HIT, including a list of valuable sources.

Objective

The objective of the HIT is to limit the consequences of natural disasters and technological accidents on the human population, hence to reduce the number of victims. To this end, the HIT is applied to identify potential secondary risks of a natural disaster and provides information that can subsequently feed into the decision making process on requests for further specialized assistance and targeted mitigation measures.

Methodology

The methodology of the HIT is based on the Flash Environmental Assessment Tool (FEAT), a rapid assessment methodology used to identify the most acute hazards to human health and the environment after natural disasters. The HIT does not replace the FEAT; on the contrary, both tools are complementary: The HIT is compiled based on a desk top research, and sent to first responders and/or national authorities for in-country verification. It is important to emphasize that the HIT is only a first step to reach the goal of limiting the consequences of secondary risks.

The HIT consists of a list of "big and obvious" facilities and objects that may pose a risk to human health and life, as well as the natural environment. The list includes indications of the hazardous substances that are expected to be present in these facilities, as well as the hazard types associated with these substances and related estimated impact types. The hazard types and estimated impact types in the HIT are based on the above mentioned FEAT to facilitate ease of complementary use.

Impact types

Direct impact on human health - Immediate adverse health effects, possibly leading to immediate death (e.g. explosion, immediate toxic effects)
Direct impact on life-support functions and nature - Immediate impact on crops, fish resources, agricultural land, water supply and iImmediate threats to biodiversity and certain species or ecosystems
Long-term impact on life-support functions, nature and humans -
Toxic persistent substances entering the food chain and natural ecosystems and effects of carcinogenic substances.

More recently, HITs have also been provided in support of disaster response preparedness activities and simulation exercises.

All HITs can be accessed via the country/disaster specific links at the right column of this page. HITs are also published at the GDACS website.

Disclaimer/Limitations of the HIT

The HIT is only an identification tool and does not provide the user with reliable recommendations for response, preparedness or mitigation activities. For this, specialized expertise from qualified and experienced actors is mandatory and on-site assessments will be needed for verification. The HIT is based on the FEAT, but a simplification thereof in the sense that it only provides an overall estimate of the hazard and impact types of the substances that can be expected to be found in the facility. While these calculations are scientifically based, hazardous substances used at a certain facility may be different from the ones listed in the HIT and impact also highly depends on the quantities of substances present. Based on the list of information sources, the HIT may not provide a conclusive list. Other hazards may not be readily identifiable and it is therefore strongly en-couraged to use additional information sources.

Wind Power Blades Energize Composites Manufacturing

2012-07-05T22:35:00.001-07:00

By Joseph A. Grande, Senior Editor

Issue: October 2008

The world's growing appetite for wind energy is transforming wind blades into one of the hottest composite applications around. The huge build-up of wind-power generating capacity—particularly in the U.S, China, and Spain—has raised a bumper crop of new plants for manufacturing these composite parts.

Click Image to Enlarge

Composite wind blades are usually molded in two halves and then glued together with an epoxy adhesive. (Photo: LM Glasfiber)

Laying up glass mat for vacuum resin infusion of a wind blade. The trend is to greater automation in blade manufacturing. (Photo: LM Glasfiber)

Sanding and finishing are labor-intensive steps in wind blade manufacturing that can be reduced with automation or improved materials and processes. (Photo: Gamesa)

The sheer size of wind blades and demanding quality requirements are two of the barriers to entry for composite fabricators. (Photo: Molded Fiber Glass Companies)

Most wind blades are made by vacuum infusion, but some are molded of epoxy prepregs. Newer prepregs are optimized for faster cures and reduced finishing. (Photo: Hexcel)

The global wind energy market has grown 23% annually for the last 10 years, says Charles Kazmierski, project manager for Lucintel, a consulting firm in plastics, composites, and other industrial markets. He expects the global wind energy market for composites to be worth about $6 billion by 2012.

The U.S. wind industry has historically experienced a roller-coaster growth cycle dictated largely by the federal government's production tax credit, which subsidizes the industry. Chronic uncertainty over periodic renewals of the tax credit led to costly boom and bust cycles for the industry from 2000 to 2005, according to the American Wind Energy Association (AWEA). Availability of the credit spurred dramatic growth from 2005 to 2007. The market could experience a setback in 2009 if U.S. lawmakers fail to renew the credit by the end of 2008.

Even with the fate of federal tax incentives still unknown, the U.S. wind industry moved forward with new manufacturing installations at breakneck pace in the first quarter of 2008, putting 1400 Megawatts (MW), or about $3 billion worth, of new generating capacity in place, reports AWEA.

This ramp-up in production has put intense pressure on suppliers of resins, reinforcements, and core materials like balsa wood and PVC foam. Suppliers are focused on meeting quality and delivery objectives as wind-turbine makers globalize their operations to meet growing demand. "Until now this was primarily a European business, but now it's a global business with supply in every major region," explains Paul Langemeier, director of global market development for epoxy supplier Hexion Specialty Chemicals.

Most observers agree that long-term growth will require technical innovation to make wind more competitive with other forms of energy. One of the key trends is the push to improve productivity. Blade manufacturing via vacuum infusion or prepreg molding is labor intensive and producers are seeking ways to reduce cycle time and cut costs. Robotic lay-up, enhanced finishing techniques, two-piece or segmented blades, and on-site manufacturing are potential tools to trim labor and logistics costs. New prepreg molding techniques are said to improve surface appearance and facilitate finishing. And resin and prepreg suppliers are introducing materials that cure faster and at lower temperatures.

As wind generating capacity increases, there is also a trend to bigger and lighter blades. Observers envision greater use of carbon fiber—despite disadvantages of higher cost and tight supplies—due to its higher stiffness and lighter weight than standard E-glass. Meanwhile, traditional E-glass and specialty glass products are holding off competition from carbon fiber through new chemistry and optimization to meet higher performance requirements.

MATERIALS & METHODS

A wind turbine is composed of several composite parts; but the blades, made of fiber-reinforced epoxy or unsaturated polyester, represent the largest use of material. Other turbine parts made of polyester include the nacelle (housing for the gearbox, generator, and other components) and the hub. The dominant processing method is vacuum resin infusion. It generates low VOCs and can evenly wet out large parts with a controlled amount of resin, thus facilitating production of lighter and less expensive blades.

Prepreg molding with a woven or unidirectional glass fabric is more costly but offers greater consistency because it already contains the matrix material (typically epoxy). Depending on blade size, either vacuum infusion or prepreg molding takes 12 to 24 hr.

Typically composed of 70% to 75% glass by weight, these aerodynamically designed blades must meet very strict mechanical requirements such as high rigidity and resistance to torsion and fatigue. High static and dynamic loads over a wide temperature range are typical during a 20-yr service life. A standard 35- to 40-meter blade for a 1.5-MW turbine weighs 6 to 7 tons.

Both epoxy and polyester, and to a lesser extent vinyl ester, shared the wind blade business in the early days but epoxy earned preferred status as blades grew longer. Polyester is easier to process and is less expensive, but epoxy offers stronger mechanical performance—particularly tensile and flexural strength—for blades longer than 26 m (85 ft). Unlike epoxy, polyester needs no post-curing but the blades are generally heavier.

E-glass is by far the most used reinforcement, while more costly carbon fiber is employed on a limited basis for greater stiffness and reduced weight in longer blades.

The barriers to entry for wind blade manufacturing are formidable. They include the physical scale of the parts, the need for competitive technology and manufacturing know-how, a good supply base, global presence, and heavy investment. There are about 12 global wind turbine suppliers and the top four hold about 72% of the market, according to Kazmierski. Most of these top manufacturers make their own blades, but some, like GE Energy, contract out to firms like Molded Fiber Glass Companies (MFG), Ashtabula, Ohio, and TPI Composites Inc., Scottsdale, Ariz. The world's leading wind turbine maker is Denmark's Vestas Wind Systems A/S (23% market share), followed by GE Energy, Spain's Gamesa (17%), Germany's Enercon, India's Suzlon (10.5%), and Germany's Siemens.

The world's leading blade maker is Danish-based LM Glasfiber A/S, which makes between 8000 and 9000 blades/yr and has 25% market share. The company started manufacturing in 1978 and has expanded operations worldwide with new U.S. plants in Grand Forks, N.D., and Little Rock, Ark. It claims to have the largest total installed base of blades today: Every third turbine worldwide is fitted with its blades.

LM uses vacuum infusion and what it calls "smart engineering" to produce polyester wind blades that are less costly than epoxy but still boast high performance. The process has been optimized to create a strong, uniform laminate with more rapid hardening, which reduces production time by several hours, according to Steen Broust Nielsen, communications director.

LM has adapted its technology to produce the industry's longest wind blade. The 61.5-m (202-ft) blade, built for a 5-MW turbine from Germany's REpower Systems, weighs 17.8 tons. The turbine has a rotor diameter of 126 m (413 ft) and the three blades cover an area almost the size of two football fields. Most remarkable is LM's ability to use E-glass for stiffness and light weight above the threshold length of 40 m where carbon fiber is generally considered.

LM uses robots and other automation to lay up glass mat in the molds and to glue the blade shells together. To streamline its process and reduce cycle time, LM is investing in new blade technology based on an undisclosed new fiber that reportedly will cut blade production time in half. Half the $12-million budget of LM's "Blade King" research program comes from the Danish National Advanced Technology Foundation. New technology is expected to boost efficiency of fiber lay-up and molding. LM is partnering with Denmark's Aalborg Univ. and Risoe DTU on fiber development and with Comfil, a Danish specialist in thermoplastic composites.

In the U.S, MFG will soon open a new facility in Aberdeen, S.D., to produce blades for GE's popular 1.5-MW turbines. MFG entered the market by making 9-m blades in the late 1980s and has watched sales climb eight-fold over the last six years, according to Carl LaFrance, wind energy manager.

Like most other blade makers, MFG uses vacuum infusion to mold glass-reinforced blades from 34 to 49 m long. Design and process optimization play a critical role, according to LaFrance. "It's all in the details; it's how you lay up the fabric, charge the mold, and how you get the resin to fill the mold." Since production volumes are just now providing opportunities for automation, MFG relies on lean manufacturing techniques and 6-Sigma principles to wring out every possible process improvement.

TPI Composites is another strong player in the U.S., with new expansions in the U.S., Mexico, and China. The company is supplying GE Energy from a new 190,000-ft2 facility in Taicang, China, and a new 316,000-ft2 plant in Newton, Iowa. VienTek, TPI's joint venture with Japan's Mitsubishi Power Systems, recently tripled its blade-making capacity in Ciudad Juarez, Mexico, to about 500,000 ft2.

TPI uses its patented SCRIMP technology, a form of vacuum infusion available for licensing. Components made with the SCRIMP process are claimed to have higher fiber content than conventionally laid-up components. TPI says glass-to-resin ratios of 70:30 or higher can be achieved, compared with the typical 50:50 ratio, resulting in lighter and stronger parts.

UNIQUE ONE-PIECE DESIGN

Most turbine makers are globalizing their operations at a rapid pace. Germany's Siemens Wind Power opened a wind blade plant in Fort Madison, Iowa, last year. Meanwhile, Denmark's Vestas announced plans in August to build a blade plant in Brighton, Colo., to supplement its existing plant in Windsor, Colo. The two facilities are expected to produce 3600 blades/yr when the Brighton plant starts up in 2010.

Siemens has an innovative process that makes blades in one piece, unlike the typical blade that is made in two shells and glued together. Siemens' IntegralBlade technology uses vacuum infusion to make glass/epoxy blades in a closed process. The molding system has a closed outer mold and an expanding, flexible inner bladder. Epoxy resin is injected under a vacuum and the blade is cured at high temperature in the mold. After curing, the blade is removed from the outer mold while the inner bladder is collapsed with a vacuum and pulled from the blade. The result is a seamless one-piece blade.

The IntegralBlade system reportedly offers several advantages, including shorter cycles and more efficient use of manpower and space. Only one mold set is required, notes Hendrik Stiesdal, chief technology officer for Siemens Wind Power. Additionally, there are no tolerance issues between the shells and structural spars. Most important is that the blade is an integral structure with no glued joints that could weaken and potentially expose the structure to cracking, water entry, and lightning strikes. The process is used to make blades 30 to 52 m long.

Spain's Gamesa, which has blade plants in Ebensburg and Fairless Hills, Pa., molds about 4500 blades/yr. The company is one of only two leading suppliers (Vestas is the other) that utilize epoxy prepreg molding. Resin is distributed more homogeneously and in consistent amounts in prepreg molding, according to Emmanuel Garcia De La Pena, v.p. of industrial operations. This ensures consistent thickness, better fiber orientation, and fewer weak points, he says, resulting in better mechanicals and lower weight than with vacuum infusion.

A smaller player in blade manufacturing is Knight & Carver, National City, Calif., a former custom boat builder that transformed itself into a wind blade repair and production specialist almost 10 years ago. The company has found a niche in the blade replacement market, producing 25-m epoxy prepreg blades in Howard, S.D. A unique feature is a pultruded spar cap that provides high strength and stiffness, according to Gary Kanaby, director of business development.

Knight & Carver also made 9-m blades for now-defunct U.S. Wind Power's 100-kw wind turbine. These were made of vinyl ester for faster curing, via a one-piece bladder molding process. In a current project with the U.S. Dept. of Energy and Sandia National Laboratories (Albuquerque, N.M.), Knight & Carver developed a 27-m blade to work better at low wind speeds but not increase loads on the turbine in strong winds.

MORE PRODUCTIVE MATERIALS

Blade makers struggling to meet burgeoning demand are looking to new materials to help raise overall productivity, reduce cycle time, and cut costs. For example, the new Airstone system of epoxy resins and hardeners from Dow Epoxy Systems expands Dow's offerings for wind blades beyond just resins. The company expects to broaden its market share by offering systems that tailor resin formulations for specific blade performance, according to Bernd Hoevel, global technology leader for wind energy. Dow's new Airstone 780 E line of epoxy infusion materials offers extended pot life, faster curing, and improved cycle time.

Hexion is working with customers to develop new products that reduce weight, improve mechanicals, and deliver "more blades per unit time," says Langemeier. Meanwhile, Huntsman Advanced Materials is developing new epoxies that provide better crack and aging resistance for longer blades. Epoxies are also the dominant adhesive for gluing blade halves. Huntsman says its new toughened system is easy to process and offers improved resistance to aging and crack propagation.

Polyester and vinyl ester suppliers are working on new formulations with improved mechanical properties. At Reichhold Inc., a new Dion vinyl ester grade provides 10% to 15% more fatigue resistance and greater overall toughness for longer, lighter blades, according to Bill Schramm, director of global business development.

Ashland Composite Polymers Div. supplies Aropol G300 and M300 polyesters to LM Glasfiber and other blade makers. The company's Derakane 601-200 vinyl ester recently won certification from Germanischer Lloyd in Germany, which oversees global standards for safety and performance of wind energy systems. The material's physical properties are reportedly better than polyester and approach those of epoxy. A key advantage over epoxy is shorter post-cure time. And a new polyester from AOC is being used by an undisclosed blade manufacturer. AOC declined to provide further details.

Glass suppliers have responded to the carbon-fiber competition for making longer and lighter blades. OCV Reinforcements came out with WindStrand direct rovings and knitted fabric based on a special glass that is said to be nearly 30% stronger, 15-20% stiffer, and 8-10% lighter than the company's current E-glass. This gives blade makers a less costly solution than carbon fiber for blades 40-m long or longer, according to Wisdom Dzotsi, Americas marketing leader. In an exclusive arrangement, a leading blade maker uses WindStrand in a vacuum infusion application.

Chemistry and sizing improvements have resulted in higher-performing glass products like new Hybon 2026 roving from PPG Industries, which boasts 10% greater fatigue resistance than standard products. PPG is also working on stiffer reinforcements that fill the gap between E-glass and more costly carbon fiber.

Finland's Ahlstrom Corp. (U.S. office in Windsor, Conn.) has launched CombiFlow, a special E-glass fabric with a PET flow layer for easier and faster resin infusion. The PET is sandwiched between two glass layers. Ahlstrom also announced plans to double capacity for specialty reinforcements in the U.S. by 2011. The capacity, aimed primarily at wind energy, will be added in two phases at Bishopville, S.C.

BIGGER, STIFFER, LIGHTER

To reduce the cost of wind energy, developers want to maximize the amount of wind power they can capture. This has spurred demand for turbines with larger MW capacity and a corresponding increase in blade length. Over the last decade, average wind turbine capacity has doubled, thus cutting by 50% the number of turbines and blades necessary to generate a certain amount of power. The average turbine generating capacity is moving from 1.5 MW to 2 to 2.5 MW. The future holds even larger turbines of 3 MW and up, particularly for offshore use. Today, the largest unit is a 7.5-MW prototype offshore turbine developed by Clipper Windpower Plc, Carpinteria, Calif. It has 50- to 60-m blades.

Many industry observers believe larger turbines will require carbon fiber to provide the necessary stiffness and light weight. Global carbon-fiber use in wind power today is only about 10 million to 12 million lb/yr, vs. over 200 million lb of glass. Vestas and Gamesa are the only top-tier firms using carbon fiber, primarily in the structural spar cap (central spine) of longer blades (40-m and up). Most carbon fiber use is in Europe, and it is applied sparingly with glass.

At a price of $10 to $13/lb, carbon fiber costs 15 to 20 times more than E-glass. So the goal is to use carbon fiber selectively for strength and stiffness without incurring high cost, says Rob Klawonn, president of Toho Tenax America, a maker of 24K tow product.

In vacuum infusion, carbon fiber is hampered by its inability to wet out efficiently, though more experienced blade makers have learned to overcome this problem. Consequently, more costly prepreg molding is the preferred and most efficient method to utilize carbon fiber. At the same time, carbon fiber historically suffers cost and availability issues. However, carbon-fiber makers argue that new capacity puts supply more in balance today. Zoltek Inc., the leading carbon-fiber supplier for wind energy, has doubled capacity at its Hungarian plant every year since 2005, reaching 26 million lb this year. Zoltek sells a 50K tow product called Panex 35 for use in wind blades.

Depending on design, the economics of carbon fiber can be favorable in blades longer than 40 m, says Tim McCarthy, Zoltek v.p. of marketing and sales. Conversely, other sources point to optimized design and engineering that allow use of E-glass in longer blades like LM Glasfiber's 61.5-m behemoth. "It will be a long time before carbon fiber is used broadly, due to its cost," says Siemens' Stiesdal, whose company is working on 52-m blade made with E-glass.

The other supplier of 50K tow carbon fiber is Germany's SGL Group. The company has a strategy of forward integration, which includes the 2007 acquisition of German prepreg maker Epo and the recent purchase of a 51% stake in Germany's Abeking & Rasmussen Rotec GmbH Co., a leading independent wind blade maker. SGL also has a majority stake in glass fabric maker SGL Kumpers GmbH, Lathen, Germany. SGL plans to double its carbon fiber capacity to 24 million lb by 2012.

PREPREG ADVANCES

Productivity improvements also highlight the latest developments in prepreg molding. Hexcel Composites Ltd. launched a new epoxy prepreg that's said to reduce cure time by 15% to 20%. A major advantage of HexPlyM19 is its low risk of uncontrolled exotherm in thick sections.

HexPly M19 reportedly reduces hot spots and allows more aggressive ramp-up rates to reach maximum cure temperature. The dwell is at a higher temperature and for a shorter time than with conventional prepregs. Faster overall cure cuts mold costs by up to 10% because less expensive tooling resins and coatings can be used, along with a less expensive tooling support system. Mold service life can also be increased, Hexcel says.

The company is working on a prepreg system with improved surface appearance to reduce finishing. To meet greater U.S. demand, Hexcel will open a new glass prepreg plant in Colorado in the second half of 2009.

Another leading prepreg supplier, Gurit in the U.K., is focused on optimizing glass content and reducing voids in cured laminates. To solve surface appearance problems, Gurit has developed Sprint IPT, an in-mold primer film that facilitates finishing and painting. Also, Gurit has developed Sprint prepregs, which consist of alternating layers of dry fabric and epoxy film, offering breathability and reduced void content.

AUTOMATION IS COMING

A small Spanish manufacturer of wind turbines and blades has developed an automated blade production process that reportedly reduces labor, cuts cycle time by 75%, and produces more consistent blades. MTorres (U.S. office in Santa Ana, Calif.) devised a patent-pending vacuum infusion process that imposes no limitation on blade length. It infuses the mold with epoxy in one shot, as opposed to multiple infusions with current systems, and also uses cool molds to manage exotherm. The infusion system has a special head and tackifier that initially adds epoxy in small amounts to stabilize the glass lay-up, according to David Champa, general manager of the U.S. division.

The turnkey system requires just five workers to run five stations for lay-up, bagging, curing, joining, and painting. A gantry system automates glass lay-up. There is also automated bagging, a special bonding fixture to join the two blade halves, and self-powered moving molds. Champa describes an almost cleanroom environment with extensive temperature-control systems and robotic finishing operations. The company is working with leading turbine makers in the U.S. and Europe and expects to commercialize it next year in the U.S. The processing system will cost between $5 million and $6 million with a two-year return on investment, according to Champa.

An extensive EU-funded research program called Upwind involves more than 40 wind energy specialists who will examine new materials and manufacturing methods for large blades from 70 to 120 m. The project is looking at natural materials like wood and bamboo and cellulose fibers from hemp, flax, and wood. These offer the same stiffness-to-weight ratio as glass and similar strength but are difficult to process, according to Povl Brondsted, head of research programs for the Risoe National Laboratory for Sustainable Energy at the Technical University of Denmark. Thermoplastics like PET and PP and bio-based resins are also being examined.

Upwind is also considering new assembly solutions to build blades in multiple sections. Also under investigation are better process controls and automation.

Wind Energy by the Numbers

The U.S. is now the world leader in wind-powered electricity generation, according to the American Wind Energy Association (AWEA). While Germany still has more generating capacity (about 23,000 MW), the U.S. actually produces more electricity from wind.

Globally, more than 20,000 MW of wind power were installed in 2007, led by the U.S., China, and Spain. This was an increase of 31% compared with 2006, according to the Global Wind Energy Council in Brussels, Belgium.

The U.S. reported a record 5244 MW installed in 2007, more than double the amount in 2006 and its third consecutive year of record-setting growth. That new capacity will generate 16 billion kwh, enough to power more than 1.5 million homes. Total U.S. wind power generating capacity grew 45% in 2007 to a total of 16.8 GW.

American wind farms will generate an estimated 48 billion kwh of wind energy in 2008, just over 1% of total U.S. electricity supply, powering the equivalent of 4.5 million average U.S. homes, according to AWEA. The U.S. average growth rate was 29% from 2002 to 2007.

Wind Turbine

2012-07-05T22:34:00.001-07:00

Background

A wind turbine is a machine that converts the wind's kinetic energy into rotary mechanical energy, which is then used to do work. In more advanced models, the rotational energy is converted into electricity, the most versatile form of energy, by using a generator.

For thousands of years people have used windmills to pump water or grind grain. Even into the twentieth century tall, slender, multi-vaned wind turbines made entirely of metal were used in American homes and ranches to pump water into the house's plumbing system or into the cattle's watering trough. After World War I, work was begun to develop wind turbines that could produce electricity. Marcellus Jacobs invented a prototype in 1927 that could provide power for a radio and a few lamps but little else. When demand for electricity increased later, Jacobs's small, inadequate wind turbines fell out of use.

The first large-scale wind turbine built in the United States was conceived by Palmer Cosslett Putnam in 1934; he completed it in 1941. The machine was huge. The tower was 36.6 yards (33.5 meters) high, and its two stainless steel blades had diameters of 58 yards (53 meters). Putnam's wind turbine could produce 1,250 kilowatts of electricity, or enough to meet the needs of a small town. It was, however, abandoned in 1945 because of mechanical failure.

With the 1970s oil embargo, the United States began once more to consider the feasibility of producing cheap electricity from wind turbines. In 1975 the prototype Mod-O was in operation. This was a 100 kilowatt turbine with two 21-yard (19-meter) blades. More prototypes followed (Mod-OA, Mod-1, Mod-2, etc.), each larger and more powerful than the one before. Currently, the United States Department of Energy is aiming to go beyond 3,200 kilowatts per machine.

Many different models of wind turbines exist, the most striking being the vertical-axis Darrieus, which is shaped like an egg beater. The model most supported by commercial manufacturers, however, is a horizontal-axis turbine, with a capacity of around 100 kilowatts and three blades not more than 33 yards (30 meters) in length. Wind turbines with three blades spin more smoothly and are easier to balance than those with two blades. Also, while larger wind turbines produce more energy, the smaller models are less likely to undergo major mechanical failure, and thus are more economical to maintain.

Wind farms have sprung up all over the United States, most notably in California. Wind farms are huge arrays of wind turbines set in areas of favorable wind production. The great number of interconnected wind turbines is necessary in order to produce enough electricity to meet the needs of a sizable population. Currently, 17,000 wind turbines on wind farms owned by several wind energy companies produce 3.7 billion kilowatt-hours of electricity annually, enough to meet the energy needs of 500,000 homes.

Raw Materials

A wind turbine consists of three basic parts: the tower, the nacelle, and the rotor blades. The tower is either a steel lattice tower similar to electrical towers or a steel tubular tower with an inside ladder to the nacelle.

The first step in constructing a wind turbine is erecting the tower. Although the tower's steel parts are manufactured off site in a factory, they are usually assembled on site. The parts are bolted together before erection, and the tower is kept horizontal until placement. A crane lifts the tower into position, all bolts are tightened, and stability is tested upon completion.
Next, the fiberglass nacelle is installed. Its inner workings—main drive shaft, gearbox, and blade pitch and yaw controls—are assembled and mounted onto a base frame at a factory. The nacelle is then bolted around the equipment. At the site, the nacelle is lifted onto the completed tower and bolted into place.

Most towers do not have guys, which are cables used for support, and most are made of steel that has been coated with a zinc alloy for protection, though some are painted instead. The tower of a typical American-made turbine is approximately 80 feet tall and weighs about 19,000 pounds.

The nacelle is a strong, hollow shell that contains the inner workings of the wind turbine. Usually made of fiberglass, the nacelle contains the main drive shaft and the gearbox. It also contains the blade pitch control, a hydraulic system that controls the angle of the blades, and the yaw drive, which controls the position of the turbine relative to the wind. The generator and electronic controls are standard equipment whose main components are steel and copper. A typical nacelle for a current turbine weighs approximately 22,000 pounds.

The most diverse use of materials and the most experimentation with new materials occur with the blades. Although the most dominant material used for the blades in commercial wind turbines is fiberglass with a hollow core, other materials in use include lightweight woods and aluminum. Wooden blades are solid, but most blades consist of a skin surrounding a core that is either hollow or filled with a lightweight substance such as plastic foam or honeycomb, or balsa wood. A typical fiberglass blade is about 15 meters in length and weighs approximately 2,500 pounds.

Wind turbines also include a utility box, which converts the wind energy into electricity and which is located at the base of the tower. Various cables connect the utility box to the nacelle, while others connect the whole turbine to nearby turbines and to a transformer.

The Manufacturing
Process

Before consideration can be given to the construction of individual wind turbines, manufacturers must determine a proper area for the siting of wind farms. Winds must be consistent, and their speed must be regularly over 15.5 miles per hour (25 kilometers per hour). If the winds are stronger during certain seasons, it is preferred that they be greatest during periods of maximum electricity use. In California's Altamont Pass, for instance, site of the world's largest wind farm, wind speed peaks in the summer when demand is high. In some areas of New England where wind farms are being considered, winds are strongest in the winter, when the need for

The nacelle is a strong, hollow shell that contains the inner workings of the wind turbine, such as the main drive shaft and the gearbox. It also contains the blade pitch control, a hydraulic system that controls the angle of the blades, and the yaw drive, which controls the position of the turbine relative to the wind. A typical nacelle for a current turbine weighs approximately 22,000 pounds.

heating increases the consumption of electrical power. Wind farms work best in open areas of slightly rolling land surrounded by mountains. These areas are preferred because the wind turbines can be placed on ridges and remain unobstructed by trees and buildings, and the mountains concentrate the air flow, creating a natural wind tunnel of stronger, faster winds. Wind farms must also be placed near utility lines to facilitate the transfer of the electricity to the local power plant.

Preparing the site

1 Wherever a wind farm is to be built, the roads are cut to make way for transporting parts. At each wind turbine location, the land is graded and the pad area is leveled. A concrete foundation is then laid into the ground, followed by the installation of the underground cables. These cables connect the wind turbines to each other in series, and also connect all of them to the remote control center, where the wind farm is monitored and the electricity is sent to the power company.

Erecting the tower

2 Although the tower's steel parts are manufactured off site in a factory, they are usually assembled on site. The parts are bolted together before erection, and the tower is kept horizontal until placement. A crane lifts the tower into position, all bolts are tightened, and stability is tested upon completion.

Nacelle

3 The fiberglass nacelle, like the tower, is manufactured off site in a factory. Unlike the tower, however, it is also put together in the factory. Its inner workings—main drive shaft, gearbox, and blade pitch and yaw controls—are assembled and then mounted onto a base frame. The nacelle is then bolted
The utility box for each wind turbine and the electrical communication system for the wind farm is installed simultaneously with the placement of the nacelle and blades. Cables run from the nacelle to the utility box and from the utility box to the remote control center.
around the equipment. At the site, the nacelle is lifted onto the completed tower and bolted into place.

Rotary blades

4 Aluminum blades are created by bolting sheets of aluminum together, while wooden blades are carved to form an aerodynamic propeller similar in cross-section to an airplane wing.
5 By far the greatest number of blades, however, are formed from fiberglass. The manufacture of fiberglass is a painstaking operation. First, a mold that is in two halves like a clam shell, yet shaped like a blade, is prepared. Next, a fiberglass-resin composite mixture is applied to the inner surfaces of the mold, which is then closed. The fiberglass mixture must then dry for several hours; while it does, an air-filled bladder within the mold helps the blade keep its shape. After the fiberglass is dry, the mold is then opened and the bladder is removed. Final preparation of the blade involves cleaning, sanding, sealing the two halves, and painting.
6 The blades are usually bolted onto the nacelle after it has been placed onto the tower. Because assembly is easier to accomplish on the ground, occasionally a three-pronged blade has two blades bolted onto the nacelle before it is lifted, and the third blade is bolted on after the nacelle is in place.

Installation of control systems

7 The utility box for each wind turbine and the electrical communication system for the wind farm is installed simultaneously with the placement of the nacelle and blades. Cables run from the nacelle to the utility box and from the utility box to the remote control center.

Quality Control

Unlike most manufacturing processes, production of wind turbines involves very little concern with quality control. Because mass production of wind turbines is fairly new, no standards have been set. Efforts are now being made in this area on the part of both the government and manufacturers.

While wind turbines on duty are counted on to work 90 percent of the time, many structural flaws are still encountered, particularly with the blades. Cracks sometimes appear soon after manufacture. Mechanical failure because of alignment and assembly errors is common. Electrical sensors frequently fail because of power surges. Non-hydraulic brakes tend to be reliable, but hydraulic braking systems often cause problems. Plans are being developed to use existing technology to solve these difficulties.

Wind turbines do have regular maintenance schedules in order to minimize failure. Every three months they undergo inspection, and every six months a major maintenance checkup is scheduled. This usually involves lubricating the moving parts and checking the oil level in the gearbox. It is also possible for a worker to test the electrical system on site and note any problems with the generator or hookups.

Environmental Benefits
and Drawbacks

A wind turbine that produces electricity from inexhaustible winds creates no pollution. By comparison, coal, oil, and natural gas produce one to two pounds of carbon dioxide (an emission that contributes to the greenhouse effect and global warming) per kilowatt-hour produced. When wind energy is used for electrical needs, dependence on fossil fuels for this purpose is reduced. The current annual production of electricity by wind turbines (3.7 billion kilowatt-hours) is equivalent to four million barrels of oil or one million tons of coal.

Wind turbines are not completely free of environmental drawbacks. Many people consider them to be unaesthetic, especially when huge wind farms are built near pristine wilderness areas. Bird kills have been documented, and the whirring blades do produce quite a bit of noise. Efforts to reduce these effects include selecting sites that do not coincide with wilderness areas or bird migration routes and researching ways to reduce noise.

The Future

The future can only get better for wind turbines. The potential for wind energy is largely untapped. The United States Department of Energy estimates that ten times the amount of electricity currently being produced can be achieved by 1995. By 2005, seventy times current production is possible. If this is accomplished, wind turbines would account for 10 percent of the United States' electricity production.

Research is now being done to increase the knowledge of wind resources. This involves the testing of more and more areas for the possibility of placing wind farms where the wind is reliable and strong. Plans are in effect to increase the life span of the machine from five years to 20 to 30 years, improve the efficiency of the blades, provide better controls, develop drive trains that last longer, and allow for better surge protection and grounding. The United States Department of Energy has recently set up a schedule to implement the latest research in order to build wind turbines with a higher efficiency rating than is now possible. (The efficiency of an ideal wind turbine is 59.3 percent. That is, 59.3 percent of the wind's energy can be captured. Turbines in actual use are about 30 percent efficient.) The United States Department of Energy has also contracted with three corporations to research ways to reduce mechanical failure. This project began in the spring of 1992 and will extend to the end of the century.

Wind turbines will become more prevalent in upcoming years. The largest manufacturer of wind turbines in the world, U.S. Windpower, plans to expand from 420 megawatt capacity (4,200 machines) to 800 megawatts (8,000 machines) by 1995. They plan to have 2,000 megawatts (20,000 machines) by the year 2000. Other wind turbine manufacturers also plan to increase the numbers produced. International committees composed of several industrialized nations have formed to discuss the potential of wind turbines. Efforts are also being made to provide developing countries with small wind turbines similar to those Marcellus Jacobs built in the 1920s. Denmark, which already produces 70 percent to 80 percent of Europe's wind power, is developing plans to expand manufacture of wind turbines. The turn of the century should see wind turbines that are properly placed, efficient, durable, and numerous.

Where To Learn More

Books

Assessment of Research Needs for Wind Turbine Rotor Materials Technology. National Academy Press, 1991.

Eggleston, David M. Wind Turbine Engineering Design. Van Nostrand Reinhold, 1987.

Hunt, Daniel V. Windpower: A Handbook on Wind Energy Conversion Systems. Van Nostrand Reinhold, 1981.

Kovarik, Tom, Charles Pupher, and John Hurst. Wind Energy. Domus Books, 1979.

Park, Jack. The Wind Power Book. Cheshire Books, 1981.

Putnam, Palmer Cosslett. Power from the Wind. Van Nostrand Company, 1948.

Periodicals

Frank, Deborah. "Blowing in the Wind," Popular Mechanics, August, 1991, pp. 40-43+.

Mohs, Mayo. "Blowin' in the Wind," Discover. June, 1986, pp. 68-74.

Moretti, Peter M. and Louis V. Divone. "Modern Windmills," Scientific American. June, 1986, pp. 110-118.

Price, Marshall. "Basement-Built Wind Generator," Mother Earth News. July-August, 1986, p. 103.

Stefanides, E. J. "Hydraulic Yaw Control Upgrades Wind Turbine," Design News. March 3, 1986, p. 240.

Vogel, Shawna. "Wind Power," Discover. May, 1989, pp. 46-49.

— Rose Secrest

Time-Management Tips That Work

2012-07-05T06:05:00.001-07:00

By Joe Mathews, Don Debolt and Deb Percival

Chances are good that, at some time in your life, you've taken a time-management class, read about it in books, and tried to use an electronic or paper-based day planner to organize, prioritize and schedule your day. "Why, with this knowledge and these gadgets," you may ask, "do I still feel like I can't get everything done I need to?"

The answer is simple. Everything you ever learned about managing time is a complete waste of time because it doesn't work.

Before you can even begin to manage time, you must learn what time is. A dictionary defines time as "the point or period at which things occur." Put simply, time is when stuff happens.

There are two types of time: clock time and real time. In clock time, there are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day and 365 days in a year. All time passes equally. When someone turns 50, they are exactly 50 years old, no more or no less.

In real time, all time is relative. Time flies or drags depending on what you're doing. Two hours at the department of motor vehicles can feel like 12 years. And yet our 12-year-old children seem to have grown up in only two hours.

Which time describes the world in which you really live, real time or clock time?

The reason time-management gadgets and systems don't work is that these systems are designed to manage clock time. Clock time is irrelevant. You don't live in or even have access to clock time. You live in real time, a world in which all time flies when you are having fun or drags when you are doing your taxes.

The good news is that real time is mental. It exists between your ears. You create it. Anything you create, you can manage. It's time to remove any self-sabotage or self-limitation you have around "not having enough time," or today not being "the right time" to start a business or manage your current business properly.

There are only three ways to spend time: thoughts, conversations and actions. Regardless of the type of business you own, your work will be composed of those three items.

As an entrepreneur, you may be frequently interrupted or pulled in different directions. While you cannot eliminate interruptions, you do get a say on how much time you will spend on them and how much time you will spend on the thoughts, conversations and actions that will lead you to success.

Practice the following techniques to become the master of your own time:

Tip 1: Carry a schedule and record all your thoughts, conversations and activities for a week. This will help you understand how much you can get done during the course of a day and where your precious moments are going. You'll see how much time is actually spent producing results and how much time is wasted on unproductive thoughts, conversations and actions.

Tip 2: Any activity or conversation that's important to your success should have a time assigned to it. To-do lists get longer and longer to the point where they're unworkable. Appointment books work. Schedule appointments with yourself and create time blocks for high-priority thoughts, conversations, and actions. Schedule when they will begin and end. Have the discipline to keep these appointments.

Tip 3: Plan to spend at least 50 percent of your time engaged in the thoughts, activities and conversations that produce most of your results.

Tip 4: Schedule time for interruptions. Plan time to be pulled away from what you're doing. Take, for instance, the concept of having "office hours." Isn't "office hours" another way of saying "planned interruptions?"

Tip 5: Take the first 30 minutes of every day to plan your day. Don't start your day until you complete your time plan. The most important time of your day is the time you schedule to schedule time.

Tip 6: Take five minutes before every call and task to decide what result you want to attain. This will help you know what success looks like before you start. And it will also slow time down. Take five minutes after each call and activity to determine whether your desired result was achieved. If not, what was missing? How do you put what's missing in your next call or activity?

Tip 7: Put up a "Do not disturb" sign when you absolutely have to get work done.

Tip 8: Practice not answering the phone just because it's ringing and e-mails just because they show up. Disconnect instant messaging.

Tip 9: Don't instantly give people your attention unless it's absolutely crucial in your business to offer an immediate human response. Instead, schedule a time to answer email and return phone calls.

Tip 10: Block out other distractions like Facebook and other forms of social media unless you use these tools to generate business.

Remember that it's impossible to get everything done. Also remember that odds are good that 20 percent of your thoughts, conversations and activities produce 80 percent of your results.

Matthews has held management roles with Subway, Blimpie, Motophoto and The Entrepreneur's Source. DeBolt is a former president of the International Franchise Association. Percival works in franchise development. They are co-authors of Street Smart Franchising from Entrepreneur Press.

Introduction: Industrial Engineering

2012-07-05T06:03:00.001-07:00

Industrial Engineering is concerned with the design, installation, improvement, evaluation, and control of technical systems. The objective of Industrial Engineering is to promote quality, efficiency, and productivity by optimizing resources while concurrently minimizing costs. The tools of industrial engineering are very diverse ranging from rigorous mathematical models and design of experiments, to continuous process improvement and operations research. Computer Simulation, neural networks, and expert systems are all tools aimed at understanding, evaluating and optimizing dynamic systems. Select from the topics below for more detailed information.

Seven Steps or Seven QC Steps

2012-07-05T06:02:00.001-07:00

The 7 QC Steps process is a structured problem solving approach for improving weak processes. This approach is known as reactive improvement. The 7 QC Steps is easy to understand and learn, easy to use, and easy to monitor.

The 7 QC steps process is structured as follows:

Step 1: Select a Theme. In this step, the weakness in the process or the problem to be solved is clarified in a theme statement. A Flowchart, a Theme Selection Matrix, or a Cause & Effect Diagram is used as a tool in this step.

Step 2: Collect and Analyze Data. This step focuses facts about the problem and discovers what types of problems occur frequently. When collecting data, you must think of all possible causes. Checksheets and Pareto Diagrams are the tools most often used.

Step 3: Analyze Causes.With sufficient data from step 2, the root cause, or fundamental cause, is found by constructing a Cause & Effect Diagram.

Step 4: Plan and Implement Solution. In this step, you brainstorm for ideas that are causing the problem and develop a solution that prevents the root cause from recurring. Then, you implement an adjustment to the process. The 4W's and 1H Matrix (What, When, Where, Who, and How Matrix) is used to develop a plan.

Step 5: Evaluate Effects.You evaluate the effects of implemented solution to make sure the solution worked and does not have unacceptable results from the comparison of data, before and after the implementation of the solution. In this step, comparative Pareto Charts and Graphs are frequently used to identify the results.

Step 6: Standardize Solution. A standardized solution is confirms that the old process is replaced with an improved process and indicates that the solution is workable. A flowchart is most often used.

Step 7: Reflect on Process and the Next Problem. In this step, you consider what the team's accomplishment was in the first 6 steps and recommend a weakness to work on next.

Blade Grinding’s Need For Speed

2012-07-05T05:59:00.001-07:00

The properties that enable nickel-alloy blades to perform effectively in the hot section of turbine engines also make the blades challenging to machine. Larry Marchand, an aerospace accounts manager for United Grinding who has 22 years of industry experience in the manufacture of turbine engines, explains why this is the case.

One reason nickel alloys are commonly used for aircraft and power-generating turbine engines is because heat transfer through these materials is very slow. Although the contoured airfoil section of a blade encounters high-temperature combustion gasses, the blade's root must remain cool to avoid softening at the point of attachment with the rotor. Slow heat transfer prevents the excessive heat from progressing from the airfoil to the root.

These nickel-alloy blades are commonly produced from investment castings that are then ground to final shape via creep-feed grinding. According to Mr. Marchand, care must be taken when grinding the blades to minimize the amount of heat that is delivered into the workpiece. Because grinding heat won't dissipate throughout the entire nickel-alloy blade, it will remain localized at the blade's surface. This can cause the material to melt and re-solidify as a recast layer that may measure 0.001 to 0.002 inch thick. The recasting of the material can change the alloy's physical properties, causing the blade to become more brittle, softer or harder. Blade performance and longevity could suffer.

Some years ago, a European consortium—AGNETA—set out to develop an alternate method for grinding turbine blades and vane segments made from nickel alloys and other materials such as titanium aluminides. This consortium was comprised of grinding equipment companies and turbine engine manufacturers. Testing was performed at Germany's RWTH Aachen University. The result was a grinding method that is similar in concept to high speed machining, as well as a profile grinding machine design from Blohm that uses linear motor drives to enable rapid workpiece positioning.

Move Quickly, Grind Lightly

This new grinding concept was coined "speed-stroke grinding." Analogous to high speed machining, the technique takes light, fast passes with the grinding wheel so that any heat generated during the operation will be expelled with the chips rather than into the surface of the blade. The concept required a new grinding machine that would allow extremely fast workpiece movement. The machine, called Prokos, was developed by Blohm and introduced to the U.S. market at IMTS 2006. Blohm is one of eight companies that are part of United Grinding, located in Miamisburg, Ohio.

The Prokos machine uses linear motor drives to move its aluminum worktable along the X and Z axes. The linear drives allow the table to move at 4,700 ipm in X and 2,000 ipm in Z. The table has an integral 200-rpm rotary torque motor that enables B-axis workpiece rotation. Simultaneous rapid movement of the worktable and rotary table allows the grinding wheel, which is brought to proper position in the A axis, to follow the curved profile of a blade or vane. Compared with creep-feed grinding processes, speed-stroke grinding using CBN wheels removes material 30 percent faster and provides 20 percent longer wheel life, according to the company.

The machine's table accepts workpieces as large as 11.8 inches (L × W × H) and as heavy as 40 pounds, which is sufficient to process most blades and vane segments. To reduce the amount of moving mass on the table, the machine's diamond-disk dressing systems are mounted directly on the machine bed on either side of the table. The vertical Y axis uses linear guideways and is driven via ballscrew. To minimize machine vibration, the machine base and cross-slide are made of the company's proprietary polymer concrete casting material.

The spindle, which has an HSK interface, is rated at 40 hp and has a maximum speed of 12,000 rpm. It can be rotated 110 degrees in the A axis to position the wheel relative to the workpiece or dressing systems. Aircraft blades often require removal of 0.06 to 0.2 inch of material, while power generation blades may require 0.2 to 0.5 inch to be removed. In a typical scenario, the wheel is first dressed, and then roughing passes are taken to approximately 0.005 inch of the blade's final size. The same wheel is then dressed again before taking the finishing passes.

In terms of process control, Mr. Marchand says speed-stroke grinding tends to be more forgiving than a traditional creep-feed grinding operation. Effective creep-feed grinding requires tight control of speeds, feeds, coolant pressure and application, coolant nozzle shape and so on. If any of these elements fall out of that tight control band (say a coolant nozzle gets bumped or coolant concentration levels are too low), problems can quickly develop as heat is generated at the workpiece surface. Because heat is delivered away from the workpiece with the chips, the process control band for speed-stroke grinding is more open. Speed-stroke grinding is also said to use a fraction of the amount of coolant that would typically be required for creep-feed grinding.

In addition to providing heat removal with the chips, speed-stroke grinding's light passes lower grinding wheel pressure on the blade. This reduces the chance that the blade's airfoil will deflect or material compression will occur at a microscopic level during grinding.

Although blades and vanes have contoured surfaces, programming such grinding operations is not as complicated as creating five-axis machining tool paths, for example. Grinding operations generally call for motion that's either straight (to produce grooves in a blade's root) or convex or concave (to match an airfoil's profile). Macros have been created for the Prokos machine to simplify the programming for these components. A programmer inputs process information as prompted by the machine's software, including geometry, workpiece size and wheel diameter (This can be done at the machine or off-line). The software then automatically generates the grinding program. The Prokos machine is currently offered with a Siemens 840D control, but a Fanuc 18i is said to be available soon.

Some blades may require a small amount of milling, drilling or chamfering in addition to grinding. The Prokos machine has a 24-station ATC that's available to allow complete machining of blades in one set-up. The toolchanger also allows multiple grinding wheels to be stored.

This image shows the linear-motor machine grinding a turbine vane using the speed-stroke method. The vane is attached to a workholding device positioned on a B-axis rotary table. The grinding wheel is positioned in the appropriate A-axis angle. Linear drives quickly move the table in the X and/or Z axis, and the B-axis rotary table simultaneously rotates the vane to grind the curved surface. The combined quick machine movements, in addition to the light cuts, allow most of the heat generated during the operation to come out with the chips, rather than into the workpiece.

__._,_.___

Gundopant

Welding guns 101: light- or heavy-duty?

On the Lighter Side

Guns for Tougher Jobs

Parting Thoughts

The value chain: No longer just for task-related processes

Successful Management - 10 Simple People Skills

The Mythical 50% Resource

When Sharing a Resource Won't Work

When Sharing a Resource Will Work

Time Share

The 50% Solution

Conclusions

Top 10 Risks of Offshore Outsourcing

The Perils Of Unskilled Labor

Avoid the ‘Bloom and Doom’ Cycle

The Three Phases of Bloom and Doom

Five Ways to Defeat the Decline

Eight Keys To Successful DOE

Heat treating of aluminum and aluminum alloys

Heat treating of aluminum and aluminum alloys

INGOT PREHEATING TREATMENTS (HOMOGENIZING)

ANNEALING

PRECIPITATION HARDENING

Quenching

Aging at Room Temperature (Natural Aging)

Precipitation Heat Treating (Artificial Aging)

Precipitation Heat Treating Without Prior SoIution Heat Treatment

Precipitation Heat Treating Cast Products

The Advantages and Disadvantages of ERP

Heading off health hazards : Guidelines for working injury free

Be Wise, Protect Your Eyes

Inhaling Airborne Contaminants

Noise Hazards

Reg:aluminum beverage cans

Project Cost Management

Got Your Money on Your Mind?

Got Your Mind on Your Money?

IT and Project Cost Control

Cost and the Project Manager

Types of Nondestructive Testing

Liquid Penetrate Testing (PT)

Magnetic Particle Inspection (MT)

Radiographic Testing (RT)

Eddy Current Testing (ET)

Ultrasonic Testing (UT)

Visual Inspection Testing (VT)

NDT Method Summary

Theory of Constraints — The Goal

Outsourcing: Pros and Cons

Think before you integrate (robotic welding)

Mistake No. 1: Underestimating What You Need

Mistake No. 2: Ignoring Peripheral Equipment

Mistake No. 3: Failing to Plan for Disaster

Mistake No. 4: Believing Robots Are Too Complicated

Mistake No. 5: Eliminating Crucial Weld Personnel

Mistake No. 6: Using Cost as the Deciding Factor

Mistake No. 7: Expecting the Robot to Do Too Much or Too Little

Mistake No. 8: Failing to Consider Robotic Welding Technology in Your Shop

Hazard Identification Tool (HIT)

Objective

Methodology

Impact types

Disclaimer/Limitations of the HIT

Wind Power Blades Energize Composites Manufacturing

MATERIALS & METHODS

UNIQUE ONE-PIECE DESIGN

MORE PRODUCTIVE MATERIALS

BIGGER, STIFFER, LIGHTER

PREPREG ADVANCES

AUTOMATION IS COMING

Wind Energy by the Numbers

Wind Turbine

Background

Raw Materials

The Manufacturing Process

Preparing the site

Erecting the tower

Nacelle

Rotary blades

The Manufacturing
Process

Environmental Benefits
and Drawbacks