Shewhart’s Great Discovery

A tribute on the 100th anniversary of the first control chart memo

May 16, 2024, marks the 100th anniversary of Walter A. Shewhart’s wonderful discovery.

Walter A. Shewhart is lauded as the Father of Statistical Process Control (SPC) and is perhaps best remembered for the SPC control chart. The first record of Shewhart’s control chart is found in a Bell Telephone Laboratories internal memo from May 16, 1924, making today the 100th anniversary of Shewhart’s wonderful discovery.

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Comments

Many thanks for that tribute

This article is a real great tribute, and should be teached in engineering schools. I found the "original" chart really interesting : although measuring a percent of defects, the lower control value is not set to zero ! In the early twentieth century, the ppm were not a sensible goal. Finding a percentage of defective parts too low compared to the average would probably have revealed a defective measurement system.

Excellent

Excellent Scott. It is rare these days to read an article on control charts (Shewhart charts or Process Behavior Charts) that gets it right. It is sad to see your paper posted under the "Six Sigma" heading. I have never seen a Six Sigma believer get control charts right. Products such as Minitab that are commonly peddled in conjunction with Six Sigma, make it worse, with nonsense such as the claimed need for normal data. The only reason for normalization is to sell more outrageously expensive and unnecessary software.

If you want software to draw control charts, use FREE software like Maxi-Q. It adheres to Dr Shewhart and Dr Wheeler's teaching. The best approach is often to draw charts by hand, to get a feel for the data.

Once again, well done. I hope lots of folk read and learn.

Three Pillars and Moving Forward

I agree with Dr. Burns, it is rare to see an accurate description of Dr. Shewhart's charts and honestly, this has always been the case. I dare say things are getting worse, not better, with all the quality fads. Dr. Deming, in 1986 said another half-century may pass before we understand the full range Shewhart's contributions. This article is a step forward. I particularly enjoyed reading about the three pillars and there are page numbers I can go back and look at. Great tribute to a great man.

Allen