Walter Andrew Shewhart (pronounced like "Shoe-heart", March 18, 1891 - March 11, 1967) was an American physicist, engineer and statistician, sometimes known as the father of statistical quality control.
W. Edwards Deming said of him:
As a statistician, he was, like so many of the rest of us, self-taught, on a good background of physics and mathematics.

Early life and education
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. When Dr. Shewhart joined the Western Electric Company Inspection Engineering Department at the Hawthorne Works in 1918, industrial quality was limited to inspecting finished products and removing defective items. That all changed on May 16, 1924. Dr. Shewhart's boss, George D Edwards, recalled: "Dr. Shewhart prepared a little memorandum only about a page in length. About a third of that page was given over to a simple diagram which we would all recognize today as a schematic control chart. That diagram, and the short text which preceded and followed it, set forth all of the essential principles and considerations which are involved in what we know today as process quality control."
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.
His work was summarised in his book Economic Control of Quality of Manufactured Product (1931).
Shewhart's charts were adopted by the American Society for Testing and 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.

Work on industrial quality
From the late 1930s onwards, Shewhart's interests expanded out from industrial quality to wider concerns in science and statistical inference. The title of his second book Statistical Method from the Viewpoint of Quality Control (1939) asks the audacious question: What can statistical practice, and science in general, learn from the experience of industrial quality control?
Shewhart's approach to statistics was radically different from that of many of his contemporaries. He possessed a strong operationalist outlook, largely absorbed from the writings of pragmatist philosopher C. I. Lewis, and this influenced his statistical practice. In particular, he had read Lewis's Mind and the World Order many times. Though he lectured in England in 1932 under the sponsorship of Karl Pearson (another committed operationalist) his ideas attracted little enthusiasm within the English statistical tradition. The British Standards nominally based on his work, in fact, diverge on serious philosophical and methodological issues from his practice.
His more conventional work led him to formulate the statistical idea of tolerance intervals and to propose his data presentation rules, which are listed below:
Walter Shewhart visited India in 1947-48 under the sponsorship of P. C. Mahalanobis of the Indian Statistical Institute. Shewhart toured the country, held conferences and stimulated interest in statistical quality control among Indian industrialists.
He died at Troy Hills, New Jersey in 1967.

Data has no meaning apart from its context.
Data contains both signal and noise. To be able to extract information, one must separate the signal from the noise within the data. Later work
In 1938 his work came to the attention of physicists W. Edwards Deming and Raymond T. Birge. The two had been deeply intrigued by the issue of measurement error in science and had published a landmark paper in Reviews of Modern Physics in 1934. On reading of Shewhart's insights, they wrote to the journal to wholly recast their approach in the terms that Shewhart advocated.
The encounter began a long collaboration between Shewhart and Deming that involved work on productivity during World War II and Deming's championing of Shewhart's ideas in Japan from 1950 onwards. Deming developed some of Shewhart's methodological proposals around scientific inference and named his synthesis the Shewhart cycle.

Achievements and honours
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.
Rule 1. Original data should be presented in a way that will preserve the evidence in the original data for all the predictions assumed to be useful.
Rule 2. Any summary of a distribution of numbers in terms of symmetric functions should not give an objective degree of belief in any one of the inferences or predictions to be made therefrom that would cause human action significantly different from what this action would be if the original distributions had been taken as evidence.

Quotes

Control chart
Common cause and special cause
Analytic and enumerative statistical studies See also

Notes

Publications

Shewhart, Walter A[ndrew]. (1917). A study of the accelerated motion of small drops through a viscous medium. Lancaster, PA: Press of the New Era Printing Company, 433 p.. LCCN 18-7524. LCC QC189 .S5. OCLC 26000657. 
Shewhart, Walter A[ndrew]. (1931). Economic control of quality of manufactured product. New York: D. Van Nostrand Company, 501 p.. LCCN 31-32090. LCC TS155 .S47. ISBN 0-87389-076-0 (edition ??). OCLC 1045408. 
Shewhart, Walter A[ndrew]. (1939). Statistical method from the viewpoint of quality control, (W. Edwards Deming), Washington, The Graduate School, the Department of Agriculture, 155 p.. LCCN 4-4774. LCC HA33 .S45. ISBN 0-486-65232-7 (edition ??). OCLC 1249225.  Articles

Deming, W. Edwards (1967) Walter A. Shewhart, 1891-1967, American Statistician, Vol. 21, No. 2. (Apr., 1967), pp. 39-40.
Bayart, D. (2001) Walter Andrew Shewhart, Statisticians of the Centuries (ed. C. C. Heyde and E. Seneta) pp. 398-401. New York: Springer.
Fagen, M D (ed.) (1975) A History of Engineering and Science in the Bell System: The Early Years (1875-1925)
Fagen, M D (ed.) (1978) A History of Engineering and Science in the Bell System: National Service in War and Peace (1925-1975) ISBN 0-932764-00-2
Wheeler, Donald J. (1999). Understanding Variation: The Key to Managing Chaos - 2nd Edition. SPC Press, Inc. ISBN 0-945320-53-1.