Imagine you are an executive in an organization that defines quality as absence of defects. How, then, would you plan to improve quality?It’s obvious isn’t it? Spend time being clear about what are defects and what are not (via specifications), find points to check for defects and, if they are found, remove them. Institute a [...]
As we saw on Part I, there are some fundamentally flawed conceptual problems with Six Sigma and its statistical underpinnings are shaky indeed.But the aspect of Six Sigma that makes it that makes it least useful as a tool to improve competitiveness is that it is based on defect detection and elimination (reduction) and not [...]
One can hardly walk into a bookstore these days without being deluged with Six Sigma volumes of one sort or the other. It seems to be an answer for every businessman’s problem from controlling quality to designing new products to guaranteeing gleeful customers. As is usually the case, with these fads, the truth is somewhat [...]
An interesting (if somewhat lengthy) piece on Wikipedia from the New York Review of books…here. I use Wikipedia a lot and have checked the accuracy of pages whose subject I know something about and find it quite good. There are sometimes little errors. For example the page on W. E. Deming one of the formulas [...]
Briefly, there are many ways to estimate the variation of a sample of values. One is to pull out your calculator and follow the instructions for calculating the standard deviation. Typically that is what they call σ (the instructions usually have that wrong. n-1 is used for s not σ ). That estimate is of all [...]
