Six Sigma Black Belts are full-time change agents who work in Six Sigma or Lean Six Sigma. Black Belts work on entire value streams or cross-functional projects. Candidates for technical leader the Black Belt position are technically oriented individuals held in high regard by their peers. They should be actively involved in the organizational change and development process. Candidates may come from a wide range of disciplines and need not be formally trained statisticians or engineers. However, because they are expected to master a wide variety of technical tools in a relatively short period of time, technical leader candidates will probably possess a background in basic mathematics (e.g., algebra.) the primary tool of quantitative analysis. College-level course work in statistical methods is recommended, but not required. Successful candidates should understand spreadsheets, presentation programs and word processors. As part of their training they will be required to become proficient in the use of one or more statistical analysis software packages.
Many Six Sigma experts have expressed doubt that Six Sigma can be used effectively in small, or even in some medium-sized, organizations. However, while the approach to deployment must be modified, it is possible for small businesses to successfully implement Six Sigma. Here is how. At the outset, several givens must be in place:
- The owner of the business supports Six Sigma completely and actively, and is willing to personally spend time on it
- The company has a routine core of work that will benefit from the process rigor of Six Sigma.
- The organization’s culture is open to change.
All businesses, but small businesses especially, must understand that Six Sigma is not a panacea. There are many aspects to business, and only some of them should involve Six Sigma. Business owners should not abandon their instincts, intuition, taste, feel for the market, competitive spirit, empathy with customers and employees, common sense or good judgment.
A business that wants to change must also meet three requirements:
- Tolerance for variation and the failures that result. Change requires variation; in fact, it is defined by it.
- “Slack,” i.e., spare resources that can be diverted to change-related activities.
- Redundancy built into its systems, so that the areas being changed can still provide essential stakeholder services.
Big companies meet these requirements easily. But such is not the case with all small businesses. Their approach to Six Sigma must be modified in the following respects.
Increasing Tolerance for Variation
Small businesses cannot afford too many mistakes. Many are flirting with the line between survival and success. Thus, when choosing Six Sigma projects, the leader should err on the conservative side, especially in the beginning. Follow the rule used by successful professional gamblers: “Do not risk more than you can afford to lose.”
Before embarking on the Six Sigma journey, small businesses will want to be sure their customers are shielded from any problems that changes might cause. Prior to deployment, they must be sure that they have installed basic quality systems. ISO 9000 has proven to be useful in this regard. When conducting Six Sigma projects, small businesses must take special care to insulate customers from unintended consequences. Also, they must be prepared to forgive and forget when mistakes are made. The safe path of the status quo may result in fewer mistakes, but it is not viable in the long run.
Slack is the amount of time the change agents (Green Belts and Black Belts) spend on Six Sigma project work. Typically, a company’s most scarce resource is human talent. Six Sigma change agents must be a company’s best employees, so slack is the most important category and the most difficult to come by. Likewise, a company must have the ability to cover the important duties of these key individuals (redundancy.) The company leadership team must prepare a plan for creating this redundancy and slack before it launches its Six Sigma effort.Creating ‘Slack’ and Redundancy
As a rule of thumb, a small business can begin deploying Six Sigma when it reaches a size where one person can devote one day per week to Six Sigma. Assuming an eight-hour day, this threshold is reached when total employment is 20 full-time equivalents (FTEs). This level of commitment is necessary to justify the time and money that must be spent training the change agent, educating the leadership and orienting employees.
This falls in line with what should be a small company’s maximum change agent commitment – 0.5 to 1 percent of its total employee hours (i.e., 20 employees [800 hours a week] means devoting no more than eight hours a week of one employee’s time to Six Sigma projects). The total time spent on change will be much greater than just the change agent’s, and will include time for team meetings and time spent by others implementing the changes. Too much change all at once can be disruptive to normal operations. The 1 percent rule will keep things manageable.
For companies with fewer than 100 employees, Green Belts should be added when total employment reaches 20 and 40 employees, rather than increasing the workload on a single individual. This is recommended for several reasons:
- It is usually easier to create small amounts of slack in different areas than it is to replace 40 percent of a key person’s time.
- It will create Six Sigma expertise in more areas of the company, which will help create a culture where Six Sigma can thrive.
- It will be easier to work on cross-functional projects if there are trained people in more areas of the company.
- It will more quickly create a change-agent community where people can learn from one another and share a common bond.
The company should consider rotating people through the Green Belt position, which will require additional training expenditures. Of course, a cost/benefit analysis should be conducted before investing in training additional people, but by then the company should have seen the benefits of Six Sigma and be willing to reinvest some of its gains to spread Six Sigma through the organization.
Growing Six Sigma
A company should stay with two or three active Green Belts – rotating Six Sigma projects among them – until the company reaches a size of about 140 employees. At this size it is large enough to have a full-time change agent, i.e., a Black Belt. Assuming that a company has two active Green Belts, its commitment to change will be 1 percent after the company hires its first Black Belt. (That is calculated as 5,600 hours x 1 percent = 56 hours, or one full-time Black Belt and two part-time Green Belts.)
It is not a good idea to replace all of the Green Belts with a Black Belt when the minimum for the 1 percent rule is reached at 100 employees. Black Belts do better when there are Green Belts with whom they can work.
Ideally the Black Belt should be chosen from the ranks of the company’s Green Belts, unless they are uninterested or clearly unqualified for the greater technical skills required of a Black Belt. An individual who not only has successfully completed Green Belt projects, but who exhibits a passion for the role is a good choice. The company will need to invest in Black Belt training, of course. Costs vary widely; a training program should be chosen on the basis of operational requirements as well as cost. If a Black Belt from outside the company must be hired, a knowledgeable consultant can help assess candidates.
As a company grows, its investment in Six Sigma process improvement projects should grow at a rate of one additional Black Belt and two additional Green Belts for every additional 140 employees. While a company has fewer than five or six Black Belts, the Black Belts should report to local supervisors.
However, when the company reaches approximately 700 to 840 employees, it should consider creating a formal Six Sigma organization headed by a full-time Six Sigma Champion. This individual should possess strong leadership skills and should report to the CEO. Black Belts are more effective when they report to a central Six Sigma organization. Typically, Black Belt success rates, measured by the value of completed projects and Black Belts who complete certification requirements, are about twice as high when Black Belts report to a Six Sigma Champion instead of a local or functional leader. There are two reasons for this. First, centrally reporting Black Belts are in a better position to work cross-functional projects. And second, local leaders often cannot resist the urge to have talented Black Belts work on their current local priorities, which, while important, are less urgent than Six Sigma projects.
In addition to insuring a tolerance for variation and failure, and creating slack and redundancy, small businesses face additional obstacles not encountered by larger organizations. Two of the more daunting challenges are lack of expertise and the especially dynamic nature of small business. Here are some suggestions for dealing with these problem areas.
Inadequate Expertise – Use leverage to create “Super” Green Belts and to provide additional Black Belt support:
- Invest in software and books on Six Sigma. This “expert in a box” approach is dangerous in the hands of amateurs or Six Sigma newbies, but it is a necessary risk.
- Get help from large customer companies and suppliers. Caution: Tap into their expertise, but be wary of getting bogged down in their bureaucracy. Some Six Sigma programs have become remarkably hidebound.
- Local college faculty often can help with statistical expertise. Caveats:
- Six Sigma is not academic research.
- Know when to cut the analysis and act.
- The KISS rule (keep it simple, stupid) applies. Be sure the faculty member uses the simplest approach possible. Choose a person who can explain things in layman’s terms. (A good test might be to ask the candidate to explain binary logistic regression.)
- The faculty member may not understand what Six Sigma is. The company’s Green Belts and Black Belts might need to guide him or her.
- Use semi-retired experts. After 20-plus years of Six Sigma, there are plenty of people around who understand it and have used it. Find them.
- Take advantage of free support: iSixSigma.com’s online discussion forums, articles and information; the International Society of Six Sigma Professionals (ISSSP), etc.
- Cut travel costs by using online training and consulting.
- Hire interns from local colleges or universities. Juniors, seniors or graduate students can provide a lot of help with number crunching, data gathering, preparation and cleansing, and many other time-consuming tasks.
- Commission projects to be done by college students. Students are frequently assigned projects by their professors, and they are looking for partners. Be one.
- Many individuals are working to be certified as Black Belts and have passed a subject matter exam, but they need successful projects. Small companies can provide project opportunities.
It is important that outsiders sign non-disclosure agreements before being given access to proprietary information. This requirement might need to be bent for professors at research universities.
Dynamic Nature of Small Business – Most Six Sigma projects take four to six months, which is often too long in a small business environment. However, long cycle times often are the result of big company bureaucracy. They are not a built-in limitation of Six Sigma. Choose projects carefully, sponsor them effectively and pursue them aggressively. A small business will find that it can successfully complete most projects in four to six weeks, instead of months.
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The questions below are from various conferences where I have presented, from reader emails, and from conversations I’ve had with colleagues and clients. If you have a question that isn’t answered here, click the Contact button to send it to me. I can’t guarantee if or when I will be able to respond to your request. Advanced warning: I don’t have all of the answers! However, I’ll do my best.
Q001 Considering Six Sigma as cultural change, what is most needed to achieve full engagement from top management? What would you recommend?
Q002 How can you calculate a number of sigmas for a non-stable process?
Q003 What are some of the results obtained by Six Sigma companies?
Q004 How much time does it take for a medium sized company to change their “bottom line thinking” to “statistical thinking?”
Q005 What are the pre-requisites for Black Belts and Master Black Belts?
Q006 Do you need to apply Six Sigma to the entire organization? That is, does it involve the whole organization without exception or does it have to be applied only in operational areas?
Q007 You spoke about the number of hours needed to train Black Belts, Green Belts, and Master Black Belts. How many hours are needed to train leadership, management, and employees?
Q008 When Motorola made the smallest cell phone in the world, that was what the customers wanted. At the same time Nokia made the cell phone that customers didn’t ask for because they didn’t know. How can you balance in Six Sigma the dimensions standards, expectations and the future? Should Six Sigma focus on the client or on the market?
Q009 I suppose that a return of $1 million/Black Belt/year is possible in a production process area. We are trying to improve business processes in our company, but the results are not having the same impact as in the production areas. Can Six Sigma guarantee results in administrative areas?
Q010 What is the cost to implement a Six Sigma project?
Q011 We know that Six Sigma is a top-down program. If we want to apply Six Sigma to a manufacturing company, which path should we follow?
Q012 In my opinion you cannot separate Six Sigma from TQM. In your opinion are they separate systems?
Answer: Moving an average organization to Six Sigma does indeed require cultural change. And, yes, accomplishing this does indeed require the full engagement of top management. To accomplish this we must remember that people in top management are no different than other people. Something motivates them to do the things they do, and if we want them to do something different we have two choices:
- Change the things that motivate them, or
- Show them that Six Sigma can help them better accomplish the things they are already motivated toward.
It is my experience that item 1 is usually not within the realm of people in lower levels of management. Thus, I recommend that item 2 be pursued. It is not difficult to determine what motivates top management. Most senior leaders make it very clear what they hope to accomplish and when. Examine press releases, annual reports, the content of operations reviews, and especially budgets. Once the key drivers of senior leadership’s behavior have been identified look at companies that have pursued similar goals by employing the Six Sigma approach. Motorola, AlliedSignal, and GE are well-known benchmarks, but there are many others. Read the annual reports of these companies as well as the comments of stock market analysts. Next, research technical articles in quality and management journals for information on the results of deploying Six Sigma and TQM. Create a “story” showing how the Six Sigma approach will lead the company to the vision of senior leadership. Finally, seek any and every opportunity to tell this story to those in charge of the company. Better still; find senior leader champions inside and outside of your company to tell the story.
Answer: If you mean how can you predict the future performance of a process that is not in statistical control, you can’t. However, it is possible to calculate the historical sigma level for an unstable process by simply using a standard normal table and allowing for the 1.5 sigma shift do it now.
Answer: As mentioned above, GE is one of the benchmark companies for Six Sigma. The chart below shows the results GE has documented from their Six Sigma projects.
Answer: This question implies that there is an “OR” situation involved in choosing Six Sigma/statistical thinking. Either we pay attention to the bottom line OR we do Six Sigma. Actually, as the GE results shown above indicate, the situation is really an AND. There is a cause-and-effect relationship between the bottom line and Six Sigma. The situation is more accurately described by “We will use Six Sigma to make our bottom line grow.” In contrast to traditional cost cutting, Six Sigma makes the bottom line grow by zeroing on those costs of the organization, which add no value for customers, shareholders, or employees, i.e., waste costs. When waste costs are reduced, the results flow directly to the bottom line. In any event, it seems to take approximately three to five years for medium to large companies to reach maturity in the statistical thinking required by Six Sigma.
Answer: See my article What is a Black Belt? You may also wish to view my artcle 101 Things a Black Belt Should Know.
Answer: Although Six Sigma may start in operational areas, mature Six Sigma organizations tend to deploy the approach throughout the entire organization. The reason is simple: the organization is a system. To reach Six Sigma levels of performance requires that the system itself be optimized. Local improvements will not deliver Six Sigma results where it counts, to the customer or shareholder. The figure below illustrates the principle of total system optimization for a manufacturing company. The idea is that neither local focus nor simple cross-functional focus will get to Six Sigma. Six Sigma requires a total system perspective.
Answer: As the numbers in the table below indicate, the training provided to the various employee groups varies widely from one organization to the next. The answers provided here should be taken as rough rules-of-thumb based on my research. Organizations must adjust their training programs to respond to their own unique circumstances. For example, a service organization short of personnel qualified to take 160 hours of Black Belt training may provide 120 hours of training and employ a larger number of Master Black Belts than a typical firm to provide additional coaching.
Approximate hours of training
Master Black Belts
Question: When Motorola made the smallest cell phone in the world, that was what the customers wanted. At the same time Nokia made the cell phone that customers didn’t ask for because they didn’t know. How can you balance in Six Sigma the dimensions standards, expectations and the future? Should Six Sigma focus on the client or on the market?
Answer: This is an excellent question. Deming made it a point that innovation is the only way to survive and prosper. This requires creativity and constant change. This in turn requires redundancy, slack, variability and a high tolerance for failure. Isn’t it strange that Six Sigma’s success requires that the organization encourage the very things that it is trying to eliminate? I call this the Six Sigma Paradox. For additional information click the Approach button on the left. You may also wish to read the article The Six Sigma Management Paradox.
Question: I suppose that a return of $1 million/Black Belt/year is possible in a production process area. We are trying to improve business processes in our company, but the results are not having the same impact as in the production areas. Can Six Sigma guarantee results in administrative areas?
Answer: It is my experience and that of my clients that the payoffs in non-production areas is at least as great as in production areas, and often more so. Production areas are generally more advanced in the application of science to their work than administrative areas. Most administrative processes have not even been mapped or measured in the past. When Six Sigma methods are applied it is common to find enormous opportunities for improvement. For example, a purchasing team identified that over 95% of the time it took for processing a typical purchase order was non-value-added. Savings of this magnitude are rare in production areas. By the way, these comments also apply to service businesses.
Having said this, I don’t think Six Sigma can “guarantee” savings. The Six Sigma approach is a proven success in hundreds of organizations in all types of industries, including services, but it is not a panacea. However, any one company’s experience might be less than expected due to a variety of conditions. These conditions include the organization’s culture, its customers, its leadership, unique market conditions, etc.
Answer: The range of costs is so great that any definitive answer to this question is meaningless. Sometimes the cost approaches zero, as when one stops doing something dumb. (This is more common than you might think!) In other cases the Six Sigma project may require an investment of millions of dollars in order to reap the benefits. Six Sigma project costs are subjected to rigorous scrutiny by the organization’s finance experts during project approval. The costs must be justified by greater benefits, either in the form of a high return on investment for the project, increased customer loyalty, safety benefits, etc.
Answer: The approach we recommend is described on this web site. Just click the Approach button.
Answer: See my article Why Six Sigma is Not TQM.
The Jan. 22, 2001, issue of Fortune contained an article that offered readers risky advice–namely, that Six Sigma could be ignored without adverse consequences.1 Don’t believe it.
To be fair, the article is directed toward investors, not managers. The author’s point is that Six Sigma alone won’t make a company successful. On that, I am in total agreement. In fact, I made the same argument in my November 1999 column, “Why Six Sigma Is Not Enough.” However, the Fortune article presents a frontal assault on Six Sigma per se, and it includes so many errors, omissions and logical fallacies that the unsuspecting leader might be led to believe that his or her company would be better off without Six Sigma. This mistaken conclusion could cause serious harm to such leaders’ companies, as well as their own careers.
In addition to the superficial arguments against Six Sigma (e.g., “Six Sigma can get downright silly”), the article levels some serious criticisms against its deployment:
While impressive at the Black Belt level, the results often don’t have any noticeable impact on company financial statements. Thus, Six Sigma success doesn’t correlate to higher stock value. This applies to 90 percent of the companies that implement Six Sigma.
- Only early adopters can benefit.
- Six Sigma focuses on defects, which are hard to objectively determine for service businesses.
- Six Sigma can’t guarantee that your product will have a market.
Let’s take a closer look at these issues. Evidence for the first point is entirely anecdotal. The article mentions that Whirlpool does Six Sigma and its stock has fallen by 12 percent during the past two years. So what? GE does Six Sigma too, and its stock price is up seven percent. Meanwhile, the Dow Jones Industrial Average is down four percent. What do these comparisons tell us about Six Sigma? Nothing. Scientific studies of the value of quality improvement initiatives show that the stock of companies that implemented TQM significantly outperformed the indexes (See Figure 1).2 Of course, there are differences between TQM and Six Sigma. (Refer to my February column for details.) Having been intimately involved in both approaches, I know Six Sigma is better than TQM.
The latecomer argument is simply ludicrous. The Fortune article states, “If Whirlpool implements it, and then Maytag does too, who wins? The consumers–those savings will mostly get passed on to them.” Even if we allow the author to argue both sides (Excuse me, but didn’t you just say there weren’t any savings?), the argument fails. If Whirlpool succeeds with Six Sigma and Maytag ignores it, as advised by Fortune, Whirlpool has a cost advantage that can be used to improve its return on investment or to capture additional market share. Latecomers have to implement Six Sigma just to keep up.
To say that Six Sigma focuses on defects is to demonstrate that you don’t really understand what Six Sigma is all about. Unlike TQM, Six Sigma goes beyond defect reduction to emphasize business process improvement in general, which includes cost reduction, cycle-time improvement, increased customer satisfaction and any other metric important to the company. The contention that service defects are, as the Fortune article’s author asserts, “mind-numbingly vague,” will likely come as a particular surprise to my service-industry readers and clients. What’s ambiguous about a customer complaint? A customer leaving you for a competitor? Errors in the customer database? A big drop in the customer satisfaction survey results? I’ll bet even Fortune’s leaders keep track of several quality metrics.
Finally, the article plays the Iridium card to prove that even Six Sigma companies like Motorola can make a mistake. Iridium was to be a satellite-based communication system, but advances in technology and changes in the market rendered it obsolete before it could be deployed.
Motorola should wear Iridium as a badge of honor. It was a daring move that failed. But in the volatile high-tech arena, the big risk is not risk of failure. As an investor, I’d be far more worried about a company that was risk-averse. Six Sigma can’t guarantee success in the marketplace. Nothing can do that. But engaging in truly risky behavior, such as ignoring Six Sigma, can greatly increase the chances of failure.
1. Clifford, Lee. “Why You Can Safely Ignore Six Sigma.” Fortune, Jan. 22, 2001.
2. Hendricks, Kevin B., and Vinod R. Singhal. “Don’t Count TQM Out.” Quality Progress, April 1999.
3. Easton, George S. and Jarrell, Sherry L. “The Effects of Total Quality Management on Corporate Performance.” Journal of Business , Vol. 71, no. 2, 1998.
“In the South Seas there is a cargo cult of people. During the war they saw airplanes with lots of good materials, and they want the same thing to happen now. So they’ve arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head to headphones and bars of bamboo sticking out like antennas he’s the controller and they wait for the airplanes to land. They’re doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn’t work. No airplanes land. So I call these things cargo cult science, because they follow all the apparent precepts and forms of scientific investigation, but they’re missing something essential, because the planes don’t land.”
“Cargo Cult Science,” 1974
“When, therefore, a man absorbed in the effect which is seen has not yet learned to discern those which are not seen, he gives way to fatal habits, not only by inclination, but by calculation.”
”That Which is Seen, and That Which is Not Seen,” 1850
It seems as if the business improvement world has more than its share of fads. Over my career, I’ve encountered statistical quality control, zero defects, quality circles, Deming/SPC, Motorola Six Sigma, TQM, business process re-engineering, lean, GE Six Sigma (with Belts and other infrastructure), and various combinations and permutations of these. In our field, the MTBF (mean time between fads) is roughly four years, nearly half the seven-year MTBF for the business community as a whole. With this large sample size (n = 9 isn’t that bad), I’ve been able to discern a pattern in the lifecycle of a fad:
- An isolated group off somewhere in the organization is doing something that’s producing excellent local results. They are discovered by others.
- A champion helps to spread the group’s message to the larger organization, and results appear there too.
- Outside organizations discover the secret and are able to replicate the results. A really big company or other prestigious source begins to tout the approach.
- The bandwagon starts to roll. Others get on board and shout their success stories to the business media.
- As demand for information on the new approach builds, the supply of talented people who understand the details is exceeded. Suddenly, people who hadn’t heard of the new approach a year ago, or who are familiar with only some of the details, are supposed experts.
- Everyone is doing it. The new approach is widely discussed in the non-business media.
- Stories begin to appear about how “Executives report that 80 percent of the attempts to do X result in failure.” First just a trickle of stories, then a flood.
- Mainstream academic institutions begin to teach the approach.
- It becomes accepted dogma that “X doesn’t work.”
- On to the next fad.
As someone who follows Six Sigma news closely, it appears to me that the approach is nearing the end of its lifecycle. As an advocate of Six Sigma for traditionally managed companies, I find this somewhat distressing. After all, there are certainly thousands of firms that could benefit from the additional rigor Six Sigma brings into the business. This is especially true of non-manufacturing firms in general, and those health care in particular. As I get older I grow increasingly concerned that someday I’ll need to go to a hospital with a minor problem, only to be killed by a medical error. So, in my own self-interest, I’ve decided to see if I can offer some suggestions to arrest the decline and fall of Six Sigma by identifying its root cause.
Six Sigma: form vs. substance
The problem begins at step 5. The pseudo-experts look at Six Sigma and they see Champions, Master Black Belts, Black Belts, Green Belts, DPMOs and a plethora of statistical tools. They see projects and all of the affiliated trappings: sponsors, teams, Gantt charts, milestones, financial validation, and software to track the project portfolio and summarize results. They see lots and lots of training and software and meetings. They see “support” from top leaders.
These are the visible forms of Six Sigma. They can be easily copied, but they won’t bring the planes in. They are not the Six Sigma that returned Motorola to competitiveness for a decade and extended the GE miracle. This is Cargo Cult Six Sigma.
What is Six Sigma, really?
Six Sigma is clarifying the desired outcomes for all stakeholders, identifying the drivers and root causes necessary to achieve them, using data wisely to help guide companies as they try to address root causes, and using a systematic approach to continuously improve.
Six Sigma uses a rigorous, focused and highly effective implementation of proven quality principles and techniques. Today, this means that Six Sigma is deployed by training a small cadre of in-house technical leaders, known as Six Sigma Black Belts, to a high level of proficiency in the application of a selected subset of project management and statistical tools. These change agents are supported by an infrastructure of leaders known as Champions and technical specialists known as Master Black Belts. The tools are applied within a simple performance improvement framework known as define, measure, analyze, improve, control, or DMAIC (a related approach, Design for Six Sigma, or DFSS, is also gaining favor). Six Sigma operates in a culture of willingness to change and tolerance for mistakes, which are inevitable when change occurs. The leaders of Six Sigma organizations build and maintain this culture.
Note that what Six Sigma is and how Six Sigma is deployed are two entirely different things. Cargo Cult Six Sigma misses what Six Sigma is and completely focuses on the visible aspects of Six Sigma. The short-term results are abysmal. The long-term result is to find yet another fad and start the whole process over again.
This isn’t the first time: Before Cargo Cult Six Sigma, we had Cargo Cult SQC, zero defects (which was almost itself Cargo Cult management,) quality circles, and so on. The problem appears to be inherent in business management culture. I discuss the solution (i.e., getting rid of management) in my book The End of Management (Atlantis Pub, 1999). However, until this can be done, organizations need to operate using the best known management approach. At the moment, that’s still Six Sigma.
In general, a Six Sigma Black Belt should be quantitatively oriented.
With minimal guidance, the Six Sigma Black Belt should be able to use data to convert broad generalizations into actionable goals.
The Six Sigma Black Belt should be able to make the business case for attempting to accomplish
Copyright © 2003
by Thomas Pyzdek, all rights reserved
- In general, a Six Sigma Black Belt should be quantitatively oriented.
- With minimal guidance, the Six Sigma Black Belt should be able to use data to convert broad generalizations into actionable goals.
- The Six Sigma Black Belt should be able to make the business case for attempting to accomplish these goals.
- The Six Sigma Black Belt should be able to develop detailed plans for achieving these goals.
- The Six Sigma Black Belt should be able to measure progress towards the goals in terms meaningful to customers and leaders.
- The Six Sigma Black Belt should know how to establish control systems for maintaining the gains achieved through Six Sigma.
- The Six Sigma Black Belt should understand and be able to communicate the rationale for continuous improvement, even after initial goals have been accomplished.
- The Six Sigma Black Belt should be familiar with research that quantifies the benefits firms have obtained from Six Sigma.
- The Six Sigma Black Belt should know or be able to find the PPM rates associated with different sigma levels (e.g., Six Sigma = 3.4 PPM)
- The Six Sigma Black Belt should know the approximate relative cost of poor quality associated with various sigma levels (e.g., three sigma firms report 25% COPQ).
- The Six Sigma Black Belt should understand the roles of the various people involved in change (senior leader, champion, mentor, change agent, technical leader, team leader, facilitator).
- The Six Sigma Black Belt should be able to design, test, and analyze customer surveys.
- The Six Sigma Black Belt should know how to quantitatively analyze data from employee and customer surveys. This includes evaluating survey reliability and validity as well as the differences between surveys.
- Given two or more sets of survey data, the Six Sigma Black Belt should be able to determine if there are statistically significant differences between them.
- The Six Sigma Black Belt should be able to quantify the value of customer retention.
- Given a partly completed QFD matrix, the Six Sigma Black Belt should be able to complete it.
- The Six Sigma Black Belt should be able to compute the value of money held or invested over time, including present value and future value of a fixed sum.
- The Six Sigma Black Belt should be able to compute present value and future value for various compounding periods.
- The Six Sigma Black Belt should be able to compute the break even point for a project.
- The Six Sigma Black Belt should be able to compute the net present value of cash flow streams, and to use the results to choose among competing projects.
- The Six Sigma Black Belt should be able to compute the internal rate of return for cash flow streams and to use the results to choose among competing projects.
- The Six Sigma Black Belt should know the COPQ rationale for Six Sigma, i.e., he should be able to explain what to do if COPQ analysis indicates that the optimum for a given process is less than Six Sigma.
- The Six Sigma Black Belt should know the basic COPQ categories and be able to allocate a list of costs to the correct category.
- Given a table of COPQ data over time, the Six Sigma Black Belt should be able to perform a statistical analysis of the trend.
- Given a table of COPQ data over time, the Six Sigma Black Belt should be able to perform a statistical analysis of the distribution of costs among the various categories.
- Given a list of tasks for a project, their times to complete, and their precedence relationships, the Six Sigma Black Belt should be able to compute the time to completion for the project, the earliest completion times, the latest completion times and the slack times. He should also be able to identify which tasks are on the critical path.
- Give cost and time data for project tasks, the Six Sigma Black Belt should be able to compute the cost of normal and crash schedules and the minimum total cost schedule.
- The Six Sigma Black Belt should be familiar with the basic principles of benchmarking.
- The Six Sigma Black Belt should be familiar with the limitations of benchmarking.
- Given an organization chart and a listing of team members, process owners, and sponsors, the Six Sigma Black Belt should be able to identify projects with a low probability of success.
- The Six Sigma Black Belt should be able to identify measurement scales of various metrics (nominal, ordinal, etc).
- Given a metric on a particular scale, the Six Sigma Black Belt should be able to determine if a particular statistical method should be used for analysis.
- Given a properly collected set of data, the Six Sigma Black Belt should be able to perform a complete measurement system analysis, including the calculation of bias, repeatability, reproducibility, stability, discrimination (resolution) and linearity.
- Given the measurement system metrics, the Six Sigma Black Belt should know whether or not a given measurement system should be used on a given part or process.
- The Six Sigma Black Belt should know the difference between computing sigma from a data set whose production sequence is known and from a data set whose production sequence is not known.
- Given the results of an AIAG Gage R&R study, the Six Sigma Black Belt should be able to answer a variety of questions about the measurement system.
- Given a narrative description of “as-is” and “should-be” processes, the Six Sigma Black Belt should be able to prepare process maps.
- Given a table of raw data, the Six Sigma Black Belt should be able to prepare a frequency tally sheet of the data, and to use the tally sheet data to construct a histogram.
- The Six Sigma Black Belt should be able to compute the mean and standard deviation from a grouped frequency distribution.
- Given a list of problems, the Six Sigma Black Belt should be able to construct a Pareto Diagram of the problem frequencies.
- Given a list which describes problems by department, the Six Sigma Black Belt should be able to construct a Cross-tabulation and use the information to perform a Chi-square analysis.
- Given a table of x and y data pairs, the Six Sigma Black Belt should be able to determine if the relationship is linear or non-linear.
- The Six Sigma Black Belt should know how to use non-linearity’s to make products or processes more robust.
- The Six Sigma Black Belt should be able to construct and interpret a run chart when given a table of data in time-ordered sequence. This includes calculating run length, number of runs and quantitative trend evaluation.
- When told the data are from an exponential or Erlang distribution the Six Sigma Black Belt should know that the run chart is preferred over the standard X control chart.
- Given a set of raw data the Six Sigma Black Belt should be able to identify and compute two statistical measures each for central tendency, dispersion, and shape.
- Given a set of raw data, the Six Sigma Black Belt should be able to construct a histogram.
- Given a stem & leaf plot, the Six Sigma Black Belt should be able to reproduce a sample of numbers to the accuracy allowed by the plot.
- Given a box plot with numbers on the key box points, the Six Sigma Black Belt should be able to identify the 25th and 75th percentile and the median.
- The Six Sigma Black Belt should know when to apply enumerative statistical methods, and when not to.
- The Six Sigma Black Belt should know when to apply analytic statistical methods, and when not to.
- The Six Sigma Black Belt should demonstrate a grasp of basic probability concepts, such as the probability of mutually exclusive events, of dependent and independent events, of events that can occur simultaneously, etc.
- The Six Sigma Black Belt should know factorials, permutations and combinations, and how to use these in commonly used probability distributions.
- The Six Sigma Black Belt should be able to compute expected values for continuous and discrete random variables.
- The Six Sigma Black Belt should be able to compute univariate statistics for samples.
- The Six Sigma Black Belt should be able to compute confidence intervals for various statistics.
- The Six Sigma Black Belt should be able to read values from a cumulative frequency ogive.
- The Six Sigma Black Belt should be familiar with the commonly used probability distributions, including: hypergeometric, binomial, Poisson, normal, exponential, chi-square, Student’s t, and F.
- Given a set of data the Six Sigma Black Belt should be able to correctly identify which distribution should be used to perform a given analysis, and to use the distribution to perform the analysis.
- The Six Sigma Black Belt should know that different techniques are required for analysis depending on whether a given measure (e.g., the mean) is assumed known or estimated from a sample. The Six Sigma Black Belt should choose and properly use the correct technique when provided with data and sufficient information about the data.
- Given a set of subgrouped data, the Six Sigma Black Belt should be able to select and prepare the correct control charts and to determine if a given process is in a state of statistical control.
- The above should be demonstrated for data representing all of the most common control charts.
- The Six Sigma Black Belt should understand the assumptions that underlie ANOVA, and be able to select and apply a transformation to the data.
- The Six Sigma Black Belt should be able to identify which cause on a list of possible causes will most likely explain a non-random pattern in the regression residuals.
- If shown control chart patterns, the Six Sigma Black Belt should be able to match the control chart with the correct situation (e.g., an outlier pattern vs. a gradual trend matched to a tool breaking vs. a machine gradually warming up).
- The Six Sigma Black Belt should understand the mechanics of PRE-Control.
- The Six Sigma Black Belt should be able to correctly apply EWMA charts to a process with serial correlation in the data.
- Given a stable set of subgrouped data, the Six Sigma Black Belt should be able to perform a complete Process Capability Analysis. This includes computing and interpreting capability indices, estimating the % failures, control limit calculations, etc.
- The Six Sigma Black Belt should demonstrate an awareness of the assumptions that underlie the use of capability indices.
- Given the results of a replicated full-factorial experiment, the Six Sigma Black Belt should be able to complete the entire ANOVA table.
- The Six Sigma Black Belt should understand the basic principles of planning a statistically designed experiment. This can be demonstrated by critiquing various experimental plans with or without shortcomings.
- Given a “clean” experimental plan, the Six Sigma Black Belt should be able to find the correct number of replicates to obtain a desired power.
- The Six Sigma Black Belt should know the difference between the various types of experimental models (fixed-effects, random-effects, mixed).
- The Six Sigma Black Belt should understand the concepts of randomization and blocking.
- Given a set of data, the Six Sigma Black Belt should be able to perform a Latin Square analysis and interpret the results.
- Ditto for one way ANOVA, two way ANOVA (with and without replicates), full and fractional factorials, and response surface designs.
- Given an appropriate experimental result, the Six Sigma Black Belt should be able to compute the direction of steepest ascent.
- Given a set of variables each at two levels, the Six Sigma Black Belt can determine the correct experimental layout for a screening experiment using a saturated design.
- Given data for such an experiment, the Six Sigma Black Belt can identify which main effects are significant and state the effect of these factors.
- Given two or more sets of responses to categorical items (e.g., customer survey responses categorized as poor, fair, good, excellent), the Six Sigma Black Belt will be able to perform a Chi-Square test to determine if the samples are significantly different.
- The Six Sigma Black Belt will understand the idea of confounding and be able to identify which two factor interactions are confounded with the significant main effects.
- The Six Sigma Black Beltwill be able to state the direction of steepest ascent from experimental data.
- The Six Sigma Black Belt will understand fold over designs and be able to identify the fold over design that will clear a given alias.
- The Six Sigma Black Belt will know how to augment a factorial design to create a composite or central composite design.
- The Six Sigma Black Belt will be able to evaluate the diagnostics for an experiment.
- The Six Sigma Black Belt will be able to identify the need for a transformation in y and to apply the correct transformation.
- Given a response surface equation in quadratic form, the Six Sigma Black Belt will be able to compute the stationary point.
- Given data (not graphics), the Six Sigma Black Belt will be able to determine if the stationary point is a maximum, minimum or saddle point.
- The Six Sigma Black Belt will be able to use a quadratic loss function to compute the cost of a given process.
- The Six Sigma Black Belt will be able to conduct simple and multiple linear regression.
- The Six Sigma Black Belt will be able to identify patterns in residuals from an improper regression model and to apply the correct remedy.
- The Six Sigma Black Belt will understand the difference between regression and correlation studies.
- The Six Sigma Black Belt will be able to perform chi-square analysis of contingency tables.
- The Six Sigma Black Belt will be able to compute basic reliability statistics (mtbf, availability, etc.).
- Given the failure rates for given subsystems, the Six Sigma Black Belt will be able to use reliability apportionment to set mtbf goals.
- The Six Sigma Black Belt will be able to compute the reliability of series, parallel, and series-parallel system configurations.
- The Six Sigma Black Belt will demonstrate the ability to create and read an FMEA analysis.
- The Six Sigma Black Belt will demonstrate the ability to create and read a fault tree.
- Given distributions of strength and stress, the Six Sigma Black Belt will be able to compute the probability of failure.
- The Six Sigma Black Belt will be able to apply statistical tolerancing to set tolerances for simple assemblies. He will know how to compare statistical tolerances to so-called “worst case” tolerancing.
- The Six Sigma Black Belt will be aware of the limits of the Six Sigma approach.