Walter A. Shewhart
Father of statistical quality control
“Shewhart simulated theoretical models by marking numbers on three different sets of metal-rimmed tags. Then he used an ordinary kitchen bowl – the Shewhart bowl – to hold each set of chips as different sized samples were drawn from his three different populations. There was a bowl, and it played a vital role in the development of ideas and formulation of methods culminating in the Shewhart control charts.” – Ellis R. Ott, Tribute to Walter A. Shewhart, 1967
Walter Andrew Shewhart (1891-1967)
Shewhart was born in New Canton, Illinois, USA on 18th March 1891. He attended the University of Illinois receiving an A.B. in 1913, then an A.M. degree in 1914. He was awarded his doctorate from the University of California in 1917.
In 1918, Shewhart joined the Inspection Engineering Department of Western Electric Company, a manufacturer of telephony hardware for Bell Telephone. He worked there on statistical tools to examine when a corrective action must be applied to a process.
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. The control chart techniques, which he developed, have been widely adopted. 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 at Bell Telephone Laboratories from their foundation in 1925 until his retirement in 1956. He expanded his interests to a broader use of statistics over this period. During this period he published many articles in the Bell System Technical Journal. In addition, he published Random sampling in the American Mathematical Monthly in 1931. In 1939 he published the important book Statistical Method from the Viewpoint of Quality Control.
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. 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.
External Links
- http://www.asq.org/about-asq/who-we-are/bio_shewhart.html
- http://en.wikipedia.org/wiki/Walter_A._Shewhart
- http://www.gap-system.org/~history/Biographies/Shewhart.html
- http://dspace.dial.pipex.com/town/square/fd80/light/shewhartbiog.htm
