Biography of Walter A Shewhart

Shewhart was born in New Canton, Illinois, USA on 18th March 1891. His schooling in physics at the Universities of Illinois and California led him to his doctorate and a brief spell as an academic.

In 1918, Shewhart joined the Western Electric Company, a manufacturer of telephony hardware for Bell Telephone. Bell Telephone’s engineers had been working to improve the reliability of their transmission systems. Because amplifiers and other equipment had to be buried underground, there was a business need to reduce the frequency of failures and repairs. Bell Telephone had already realised the importance of reducing variation in a manufacturing process, the basis of all lean production. Moreover, they had realised that continual process-adjustment in reaction to non-conformance actually increased variation and degraded quality. In 1924, Shewhart framed the problem in terms of "assignable-cause" and "chance-cause" variation and introduced the "control chart" as a tool for distinguishing between the two. Shewhart stressed that bringing a production process into a state of "statistical control", where there is only chance-cause variation, and keeping it in control, is necessary to predict future output and to manage a process economically. Shewhart worked to advance the thinking at Bell Telephone Laboratories from their foundation in 1925 until his retirement in 1956, publishing a series of papers in the Bell System Technical Journal.

During the 1930s, Shewhart’s work led him to fundamental scientific and philosophical issues, particularly those concerned with operationalism. It was this work that led him to his review of the measurement of the speed of light.

In 1932 E S Pearson read a paper to an Ordinary meeting of the Royal Statistical Society in London, England describing Shewhart's ideas in mathematical terms. This, together with Pearson's paper of the following year, started a long tradition of misunderstanding and obfuscation of Shewhart's ideas in the UK.

Shewhart’s charts were adopted by the American Society for Testing Materials (ASTM) in 1933 and advocated to improve production during World War II in American War Standards Z1.1-1941, Z1.2-1941 and Z1.3-1942. It was during this period that W Edwards Deming founded a systematic critique of data-based management, premised on Shewhart's insights. Following the war, Deming went on to champion Shewhart's methods, working as an industrial consultant to Japanese, and latterly US, corporations from 1950 to 1990. Deming's systematic strategy for business improvement was responsible for a dramatic increase in Japanese productivity over that period.

Shewhart received many awards including the Holley Medal of the American Society of Mechanical Engineers and Honorary Fellowship of the Royal Statistical Society and American Society for Quality. For twenty years he was editor of the Wiley Series in Mathematical Statistics. He died at Troy Hills, New Jersey, USA on 11th March 1967.

During the 1990s, Shewhart’s genius was re-discovered by a third generation of managers, naming it the "Six Sigma" approach.

Shewhart quotes

"Both pure and applied science have gradually pushed further and further the requirements for accuracy and precision. However, applied science, particularly in the mass production of interchangeable parts, is even more exacting than pure science in certain matters of accuracy and precision."

Shewhart links

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This page last updated 17th September 2001

copyright ©2001 by A N Cutler