After many years of blogging, and consistent with my desire to move toward retirement, we have ended the Insights blog. Thanks to Doug Bedell for his years of blog support.

Keeping Statistics Simple, Yet Profound

Posted on May 12, 2011
Filed Under Business, Government | Leave a Comment

Knowing what we’re doing requires ready, reliable observational methods – preferably, a method. The best method we know (though we wouldn’t claim to be expert in it) is statistical process control (SPC) based on principles espoused by the late Dr. W. Edwards Deming and the work and writings of Deming disciples like Donald J. Wheeler.

Dr. Deming was a godlike statistician who had a profound understanding of his discipline, so profound that he expressed it simply, and really caught your attention (if only on videotapes) with questions like: “What do you want to accomplish?,” “By what method will you accomplish it?” and “How will you know?”

Donald Wheeler had the good fortune of meeting Dr. Deming in 1972, working with him thereafter and writing or editing materials about him. He and his wife, Fran, founded SPC Press in 1986, which published Deming’s biography, The World of W. Edwards Deming, by his long-time secretary, Cecelia S. Kilian, in 1992. (Dr. Deming’s own “bible,” Out of the Crisis, was published by MIT a decade or so earlier.)

We noted that Don Wheeler is to receive the 2010 Deming Medal from the American Society for Quality (ASQ) in Pittsburgh this weekend, and felt it appropriate to note Dirk Dusharme’s May 4 interview with him at Quality Digest.

“For years,” Wheeler says, “I observed managers telling Deming all the good things that they were going to do and heard him respond with one of two questions: ‘By what method?’ or ‘How will you know?’ It is just that basic. Until you can answer these two questions, all you have is wishful thinking.”

Making effective use of observational and measuring techniques is being complicated these days by the availability of statistical software packages and the vogue of Black Belt quality training. “One company I worked with,” Wheeler recalls, “taught its Black Belts a list of 56 statistical techniques. When I came around, the first question was always, ‘When do I use the different techniques?’ In answer to this question I wrote another 400-page book.” Not the way to go on a factory floor.

“…we do not need more statistical techniques,” Wheeler adds, “but more managers, engineers, and scientists trained in the fundamentals of how to make sense of their data. In my experience, a well-taught SPC class achieves this objective much faster, and much more effectively, than the traditional curriculum of descriptive statistics, probability theory, and statistical inference that is focused on the analysis of experimental data.”

He recalls a project for the U.S. Department of Transportation (DOT) that sought to determine how different types of parking – parallel vs. angle – affected mid-block accident rates on a street. With an SAS 76 software package, he got “a beautiful analysis, complete with a printout of all of the (complicated) comparisons used to find each of the different types of sums of squares. At this point, I knew the answers, but I found that I could not explain them to the engineers in such a way that they could, in turn, explain them” to DOT.

So by using a simpler observational technique, he explained that it was the amount of parking on the street that mattered, not its angle. “Any type of on-street parking is perfectly safe – as long as no one uses it!”

Being alert and attuned to basic principles matters a lot in seemingly complex times. That was Dr. Deming’s message, and it’s Donald Wheeler’s as well – one well worth living, observing and learning by. – Doug Bedell


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