# isixsigma.com

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On its way to disrupting the historical business continuum and changing its performance trajectory, an organization passes through a number of milestones.  Assuming a “typical” business, our discussion begins at time T1.  This is when the organization is functioning reasonably well — a stable force in its industry, capable of maintaining itself reasonably well. The […]

## I have a great deal of data but don’t know where to start on my Green Belt project. What do you suggest?

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Get the book “Six Sigma for Everyone” by George Eckes, John Wiley and Sons 2003.  It does a very nice job of outlining what to do and provides some really good tools.  Seems like a good book for green belts. To extend beyond the aforementioned book, let us come to understand the importance of properly […]

## Is RTY Better to Use Even If It May Not Show a Cost Savings?

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Do not employ money as the improvement variable (it is a symptom). Remember that RTY is a function of dpu. Since RTY and dpu are directly related, most would likely prefer the defect-centric metric.

## How Well Does Rolled Throughput Yield Work as a Primary Metric?

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Upfront, rolled throughput yield has a lot of sex appeal (and is an excellent instructional concept), but many discontinue its application after a short period of time – it is impractical for a relatively complex process. Recognize that most of the defect-centric metrics are usually better for purposes of quality reporting (and improvement efforts).

## How Can I Determine If My Rolled Throughput Yield (RTY) Is Acceptable?

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Let us postulate that a certain process is comprised of three progressive steps, say A, B, and C, respectfully. Further, we note the observed defects-per-unit (dpu) at the first step to be dpu.A = .10. At the second step, dpu.B = .05. The third step was found to be dpu.C = .008. Of course, we acknowledge dpu as a […]

## How can Six Sigma be extended to the maintenance field to enhance our machine Mean Time Between Failure (MTBF??

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As you likely know, equipment uptime (as well as downtime) is very much akin to product reliability engineering.  Many of the same concepts, equations, and methods are commonly shared.  Given this, it should be interesting to note that Six Sigma found its genetic roots in the field of reliability engineering.  As some of the more […]

## Can I Extrapolate 3.4 Defects Per Million to 34 Defects Per 10 Million or 3400 Defects Per Billion?

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To help you better understand the nature of this question; let us consider a very simple example.  Let us suppose that we go to the store – looking for fresh apples.  Once there, we notice a sign that reads “3 apples for \$1.00.”  Based on this sign, we ask the storekeeper: “If I want to buy […]

## How can Six Sigma be applied to the Human Resources (HR) function?

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You should reference the article submitted by Anonymous on 17 July 2003.  Truly, it is this form of reasoning (coupled with this example) that should “get you thinking in the right direction.”  Listed are some simple examples for Human Resource projects: 1) Employee turnover rate.2) Job satisfaction issues (surveys).3) Management satisfaction.4) Cafeteria food quality.5) Policy […]

## My Boss Calculates Our Process Sigma at 3 Sigma, While I Calculate It at 5 Sigma. Who Is Correct?

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Perhaps you are both in error (as related to your Sigma calculations.) Do not be discouraged by such debate, as it is quite common among those new to Six Sigma. However, do be aware of a phenomenon I call “denominator management.” This colorful term is used to describe the practice of inflating or otherwise distorting the denominator […]

## What type of curriculum would you recommend for sales and marketing professionals who are focussed on increasing market share?

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Generally speaking, the Six Sigma curriculum (i.e., Black Belt, Green Belt, and so on) for just about any type of service or support activity can be easily found these days – everybody has their idea of what such curriculum should consist of.  Perhaps of more concern, is the idea of “curriculum integrity,” as it is […]

## Is Six Sigma just as valid for service providers as it is for manufacturers?

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So as to better appreciate the spirit and intent of our ensuing discussion, we must call upon the nature and purpose of two recognized entities – the US Postal Service and Ford Motor Company.  If we were to contrast these organizations, how would they appear to be similar? How would they appear to be dissimilar?  […]

## What is the difference between Lean Six Sigma and Six Sigma?

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Lean Sigma might be an anorexic standard deviation. If this is true, then Lean Six Sigma is probably the linear sum of six anorexic sigmas. I would imagine that a healthy diet, mental exercise, and less greed would improve the current trend. That’s the funny thing about people with anorexia – they truly believe “skinnier […]

## How can Six Sigma be applied in a software development?

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There is a clear tendency among many new comers to Six Sigma.  That tendency is to artificially and unwittingly limit the scope of Design-For-Six-Sigma (DFSS) to the configuration of hardware-based products and processes.  As a result, it is currently common to equate DFSS with such fields of practice as engineering and manufacturing, which have their […]

## Must a Black Belt use all Six Sigma tools on every project? Is it common not to use all tools?

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1) There is no such thing as a one-size-fits all Black Belt or Green Belt program of study. 2) Many customers are naïve.  They often want more tools (not fewer), regardless of whether or not they will ever be used. 3) Some customers seek to purchase a hardware store so as to fix the kitchen […]

## What Is the Correct Manner to Count Defects and Opportunities, Used for Calculating Process Sigma Value?

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As you likely know, the issue of opportunity counting is somewhat illusive. It is laced with many misconceptions. The seeming intuitive nature of a “defect opportunity” runs wider and deeper than what one would naturally expect. To help us better understand this concept (and some of the related pitfalls), we will discuss the classic quality metric […]

## I am new to Six Sigma…how can I apply Six Sigma in my organization?

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Here are 7 progressive questions to help plan a project. 1) What decisions must be made? 2) What do you need to know to make each decision? 3) What form of visual will provide the information? 4) What kind of tool will generate the visual? 5) What kind of data is needed for the tool? […]

## Many times people are skeptical of the benefits of Six Sigma. How can we counter this type of argument and show them the benefit?

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Success factors such as business goal setting, global deployment planning, black belt project selection criteria and Six Sigma curriculum design are just a few of the key components that must be riveted together to form a common and uniform structure.  If the guiding blueprint cannot properly specify how the components fit together, it is likely […]

## I am gathering attribute data. Sample size is 5 pieces. I collect 20 samples with zero defect. How do I calculate ppm and Cpk?

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Under the condition that D = 0 defects for the constrained condition of N = 20 samples, we can statistically approximate the short-term capability and provide its quantity in the form Z.st = 3.33.  Of course, this is directly equivalent to Cp = 1.11. Interestingly, the statistical base underpinning this set of computations is fully […]

## Is there a standard exit document/checklist in template form that provides a step-by-step process to follow during project close-out that ensures all control steps are in place?

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I am not aware of a “standardized” exit document (in template form) that is related to the closeout of deliverables.  Of course, corporations often create such devices to serve their own internal needs, but are not usually postured to publicly share the resulting intellectual property.  I would suggest that you post this question on the […]

## How Can One Calculate the Sigma Level of a System at a Business Level (For Example, a Marketing System)?

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Consider the case where a particular system is comprised of three subordinate elements. In this case, we will say the first-time yield (quality confidence) of each element is known to be .85, .90, and .95, respectively. The cross product would then be given as .85 x .90 x .95 = .612, or about 61.2 percent.  This value […]

## The Sigma Conversion Table Displays Yields That Don’t Match My Understanding of USL/LSL for the Process. Could You Please Explain Why There Is a Discrepancy?

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To facilitate an answer to your question, consider the following table. The first column is the given measure of process capability (provided in the form of Z).  The second column is the corresponding short-term yield of the first column (based on a one-sided specification). Of course, the third column is the associated long-term yield, also predicated on […]

## What is the difference between SPC and SQC?

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There is little difference between Statistical Quality Control (SQC) and Statistical Process Control (SPC).  At one time, there might have been some philosophical separation, but today, they exist as general synonyms.  Some prefer SQC because the idea of “quality” is larger and more encompassing than that of “process.”  Others counter this by pointing out that […]

## How do you determine the Xs in the analyze phase of DMAIC?

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Establishing the initial list of potential causes is often more art than science.  Unfortunately, the brainstorming process is still one of the best ways to surface candidate variables.  However, there are several other alternatives: 1)   Query process experts. 2)   Benchmark similar processes. 3)   Review the literature. 4)   Perform an Internet search. 5)   Conduct correlation study. […]

## How do you apply Six Sigma in a small factory?

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Same as a big factory, but in a small way.

## Can you explain "degrees of freedom" and provide an example?

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To facilitate an answer, we will consider three examples.  First, consider the game of baseball.  We understand the field-of-play consists of 9 positions.  The coach is “free” to assign any of the 9 players to any of the 9 positions. Once the 8th player is assigned to the 8th position, the 9th player-position is pre-determined, […]

## Can you suggest a specific quantifiable problem in Robust design and/or Six Sigma for PhD studies?

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Suppose we consider a specific bilateral critical-to-quality characteristic (CTQ).  In other words, we are in view of a key design feature that sports a two-sided performance specification.  If a bilateral design margin of “Y percent” was to be imposed on the given CTQ (during the course of product configuration), we indirectly and necessarily infer the […]

## Can you explain "degrees of freedom" in the context of a Six Sigma tool, such as a DOE?

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Let us suppose we are interested in testing the influence of a certain independent variable (say, A) as it relates to a given dependent variable (say, Y).  We will suppose the experimental factor (variable A) is to be tested at two competing settings (test levels).  In this scenario, the two levels will be called “high” […]

## What is the relationship between Six Sigma and the Capability Maturity Model (CMM) for software development?

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Based on the nature of your question, I would assume you are referencing the “Capability Maturity Model Integration” system and “Capability Maturity Model”, or CMMI and CMM, respectively.  My understanding is that CMM is a generalized model for judging or otherwise assessing the maturity of software processes.  In addition, it is a means for identifying […]

## What is the relationship between Six Sigma and Management Information Systems (MIS)?

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At the onset of this discussion, it is vital that we establish the basic nature and character of a “Management Information System.”  According to G. Davis and M. Olson in the publication “Management Information Systems” (1984, p. 5-6):  “There is no consensus of the definition of the term ‘management information system’…” In fact, these highly […]

## How can Six Sigma be applied in an organization that designs, manufactures, assembles and presure tests oil drilling equipment?

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You apply Six Sigma in the same way as any other business enterprise.  In general, this means you must implement Six Sigma on a project-by-project basis.  Generically speaking, Y=f(X) and the only thing that changes from situation-to-situation is the variable labels, transfer function, rate of replication, cost-per-transaction,  and faces of the players.  Other than that,  […]

## What are the roles of the director, champions, and MBBs in order to ensure Six Sigma deployment sucess?

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As many corporations have experienced and attested, Six Sigma is a dynamic and evolutionary initiative that can produce phenomenal change in business performance.  However, the process of change must be carefully designed, managed and governed if it is to realize its aim.  Such factors as business goal setting, global deployment planning, black belt project selection […]

## How can Six Sigma failure be avoided when dealing with company cultural issues?

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Today, many business leaders would agree that the “culture of an organization” is not a fixed quantity or preordained destiny.  Rather, it results from the unique blending of values (at the business, operations, process, and individual stratums).  In this context, the idea of a “value” is akin to that of a belief or truth.  For […]

## If a company is looking for a proven tool to elevate its performance to the next level, which would you recommend?

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With respect to your question, my thinking may appear to be somewhat out-of-context. Nonetheless, it is my opinion that the premier tool, to be held in revere above of all others, is leadership. Tools such as Six Sigma, Lean, TQM, ISO, and all the rest are merely “enablers” of leadership. Not the other way around, […]

## Is there any difference in DMAIC between manufacturing and service companies? What about in different functions in the internal organization?

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As we consider the DMAIC process, it is important to bear in mind the fundamental principle of determinism: Y = f (X).  Of course, Y is the outcome variable and X is the many variables that induce Y to exist.  For any given problem-solving situation, we are behooved to recognize how DMAIC relates to Y […]

## Why Is 1.5 Subtracted From the Short-term Estimate of Capability (Z.st) to Get the Long-term Estimate of Capability (Z.lt)?

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The capability of a process has two distinct but interrelated dimensions. First, there is short-term capability, or simply Z.st. Second, we have the dimension long-term capability, or just Z.lt. Finally, we note the contrast Z.shift = Z.st – Z.lt. By rearrangement, we assuredly recognize that Z.st = Z.lt + Z.shift and Z.lt = Z.st – Z.shift. So as to better […]

## Is it Possible to Determine a Corporate-wide Sigma Level? How Can the Sigma Level be Calculated?

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So as to establish a corporate-level sigma value (per se), it is generally advisable to follow an established analytical model. Of course, any such model must be conducive to the hierarchical aggregation (pooling) of capability information and data. Generally speaking, the more common approaches for realizing this aim are inclusive of, but not limited to: 1) the […]

## How can I determine if Six Sigma will work in my organization?

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Determining if some initiative can “fit” an organization is much like buying a pair of shoes – you can know the exact size of each foot, but sooner or later, you must put the shoes on and walk around a little.  There is no substitute for experience. Six Sigma is an idea-centric, tool-based, fact-driven, top-down, […]

## Is there a difference between Six Sigma and "robust design"?

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Where the engineering of quality is concerned, Dr. G. Taguchi popularized the idea of “robustness” in the mid 80’s.  As one might suspect, the underlying definition of this term is fairly simple – per the dictionary, it is the ability to recover from unexpected [and expected] conditions during operation.   In this sense, the idea of […]

## Is 7 Sigma Possible?

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Don’t know, never been there – I’m still striving for 5-sigma (at least on a personal level). Given where the world is right now, many followers of Six Sigma (including myself) would say that a capability of 7-sigma is pessimistically possible, but not pragmatically probable. Maybe when I hit a 5-sigma level of capability, I can […]

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## Can you please explain "acceptance sampling"?

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Arguably, acceptance sampling is an effective and efficient means to ensure the proper surveillance of product and service quality.  Using this approach, a random sample (of product or service) is inspected or tested to determine if the observed level of quality is acceptable or unacceptable.  If the sample supports the hypotheses of unacceptability, then certain […]

## How Do I Determine Defects Per Million (DPM) for Sigma Values Greater Than 6 (3.4 DPM)?

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Once is a great while, there is a need to estimate or otherwise approximate the tail probability of an extreme standard normal deviate – such as Z = 7, Z = 10, or even higher.  For example, certain types of reliability problems rely on such assessments. But as many already know, most published tables of […]

## How Is the Defects Per Million Opportunities (DPMO) to Sigma Level and Yield Conversion Chart Determined?

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We must understand the sigma of a process is merely an equivalent unilateral figure-of-merit. As such, it is always regarded (and reported) as a short-term measure of capability. The metric can be directly computed when continuous data is at hand, or it can be statistically synthesized from discrete data. In the latter context, a reported sigma is only […]

## How can I implement Six Sigma in my company if I only have a basic understanding of Six Sigma?

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Asking for the optimal way to sell an organization on the merits of Six Sigma is much like asking how two people how they can best develop “love and admiration” for each other.  Your intent and focus is laudable, but your personal “brochure” is most likely “a little on the light side,” especially when given […]

## How can Six Sigma be used to improve “market forcasting,” which is essential for business planning?

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Where the idea of “process improvement” is concerned, it is now well understood that Six Sigma can play a most decisive role.  Specifically, it can serve to significantly improve the process of market forecasting. For example, consider the instance where an organization attempts to deploy a certain type of ARIMA model from which to forecast […]

## How do you suggest I process map a process like "deliver enhanced value to the customer"?

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Please recognize that the “art and science” of process mapping is quite generic by nature.  You should apply the mapping tools, techniques, and procedures in the given situation just as you would in any other type of situation.  Granted, the variable labels will change – but that’s about it.  Simply stated, you must define what […]

## Is there any experience with improving the adhesion of water based paint (spray system) on metal surfaces?

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Thanks to modern technology, we have before us a virtual mountain of information.  On the Internet, we can find many case studies on the subject of DOE (design-of-experiments).  For a wide area success stories and general discussion, you may want to visit the following websites: 1) http://www.statease.com/articles.html2) https://www.isixsigma.com/tt/doe/3) http://class.et.byu.edu/mfg340/lessons/designofexperiment/4) http://members.cox.net/asqsd/kn/publications.htm In addition to these sources, […]

## Would a lead-time reduction project for an order fulfillment process be considered a Six Sigma project or a lean project?

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This is much like asking if you have ever been caught in a lie.  No matter how you answer, the resulting conclusion will certainly not enhance your reputation – but will most assuredly harm it (perhaps even more so than currently exists).  If you were to contend that your project should be garbed in the […]

## How can defense products be designed with Design for Six Sigma (DFSS), and can you provide an example?

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Generally speaking, we use DFSS to close value-based gaps during the design phase of a product, service, business deal, or just about anything that adds value. Of course, this is accomplished in such a way that another gap is not propagated somewhere else in time and space.  In other words, we leverage the ideas and […]