Content by John Flaig

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John Flaig
Story update 9/26/2017: The words "distribution of" were inadvertently left out of the last sentence of the second paragraph. Some practitioners think that if data from a process have a “bell-shaped...
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John Flaig
Independence is an important issue in statistics, so I found the article, “Ethics, Auditing and Enron,” by Denis Arter and J. P. Russell, in the October 2003 issue of Quality Progress quite...
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John Flaig
In a similar vein to Donald Wheeler’s excellent article on process capability confusion I would like to submit the following example of thinking that you are doing the math right and getting an...
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John Flaig
Sometimes when authors try to make a technical concept more understandable, it’s simplified but unfortunately, less accurate. For example, when the developers of Six Sigma wanted to explain...
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John Flaig
I have discussed the economics of project management numerous times in presentations all over the country, and based on the response to my message, I have to conclude that many people just don...
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John Flaig
The classic version of FMEA is an engineering tool for quality and reliability improvement through project prioritization. It was formally released by the U.S. government with MIL-P-1629 in 1949...
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John Flaig
Engineers have used safety margins for centuries to protect their companies and customers from the consequences of product degradation and failure. Sometimes the safety margins are fairly obvious (...
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John Flaig
The claim is made and widely believed that C = 0 sampling plans are more cost effective than classic sampling plans such as ANSI/ASQ Z1.4. Below is a preliminary analysis of the cost difference...
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John Flaig
What’s wrong with root cause analysis? Let’s begin with the name, which is singular. It implies that there is only one root cause, when in reality most problems are usually caused by a complex...
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John Flaig
Everyone in the quality world is familiar with the famous 80–20 rule for corrective action project prioritization. The “rule” suggests that 20 percent of the causes result in 80 percent of the...