I spent my June and July articles beating up on the “sigma” index commonly associated with Six Sigma (and continue to do so over in my discussion board.) Let me sum up by saying that, while not wrong, “sigma” isn’t an efficient metric for accomplishing what we are trying to do in today’s business environment. Is there a better way to do that? I think that there is, and in this, my lucky 14th Heretic article, it is fitting that we continue to explore ways to measure the effect of Six Sigma.

Measuring quality
First we have to define quality. As I mentioned in my last article, we used to define “high quality” as conformance to specification. It was “low quality” if it was out of specification. This understanding of quality began to change as we learned that there were losses due to variation, even within the specification.

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