Content By Rip Stauffer

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By: Rip Stauffer

A lot of people in my classes struggle with conditional probability. Don’t feel alone, though. A lot of people get this (and simple probability, for that matter) wrong. If you read Innumeracy by John Allen Paulos (Hill and Wang, 1989), or The Power of Logical Thinking by Marilyn vos Savant (St.

Rip Stauffer
By: Donald J. Wheeler, Rip Stauffer

How do extra detection rules work to increase the sensitivity of a process behavior chart? What types of signals do they detect? Which detection rules should be used, and when should they be used in practice? For the answers read on.

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By: Rip Stauffer

Recently, in one of the many online discussion groups about quality, Six Sigma, and lean, this question was posed: “Can X-bar R and X-bar S be used interchangeably based on samples size (n) if the subgroup size is greater than one and less than eight?” Answers varied, of course.

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By: Rip Stauffer

A number of recent articles in quality literature (and in the quality blogosphere) have posited the death or failure of Six Sigma. More articles, from many of the same sources, discuss the outstanding success of current Six Sigma efforts in manufacturing, healthcare, government, and financial services organizations. Which is it? Is Six Sigma dying, or is it alive and well?

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By: Rip Stauffer

In one recent online forum, a Six Sigma Black Belt asked a question about validating samples—how to ensure that when they are taken, they would reflect (i.e., represent) the population parameter. His purpose: to understand the baseline for a project. He said he had six months of data regarding cycle times for handling maintenance tickets.

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By: Rip Stauffer


Editor’s note: In response to Kyle Toppazzini’s article, “Lean Without Six Sigma May Be a Failing Proposition,” published in the Sept. 27, 2012, issue of Quality Digest Daily, Rip Stauffer left the following observant comment.

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By: Rip Stauffer

I recently closed the doors of my own consulting company on the prairie in Minnesota and headed back into the wild, wacky, wonderful world of larger consulting groups, joining a group in Northern Virginia. One of the consequences of that transition was that I was unable to meet a couple of speaking engagements, so I promised to write something about dashboards for the people who had planned to attend. This dashboard issue is one of the more egregious problems I see regularly.