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

Published:

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?

Published:

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” […]

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

Published:

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, […]

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

Published:

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?

Published:

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?

Published:

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 7 Sigma Possible?

Published:

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 […]

## Can you please explain "acceptance sampling"?

Published:

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)?

Published:

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?

Published:

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?

Published:

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?

Published:

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 […]