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
Statistical process control (SPC) or statistical quality control (SQC) is the application of statistical methods to monitor and control the quality of a production process. This helps to ensure that the process operates efficiently, producing ...
'' and also related to the
Shewhart cycle.
W. Edwards Deming
William Edwards Deming (October 14, 1900 – December 20, 1993) was an American engineer, statistician, professor, author, lecturer, and management consultant. Educated initially as an electrical engineer and later specializing in mathematical ...
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.
Born in
New Canton, Illinois
New Canton is an incorporated town in Pleasant Vale Township, Pike County, Illinois, United States. The population was 359 at the 2010 census, a decline from 417 in 2000.
Geography
New Canton is located about 26 miles southeast of Quincy along ...
to Anton and Esta Barney Shewhart, he attended the
University of Illinois at Urbana–Champaign
The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the Univer ...
before being awarded his doctorate in physics from the
University of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...
in 1917. He married Edna Elizabeth Hart, daughter of William Nathaniel and Isabelle "Ibie" Lippencott Hart on August 4, 1914 in Pike County, Illinois.
Work on industrial quality
Bell Telephone
The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over one hundre ...
’s engineers had been working to improve the reliability of their
transmission system
:''See Transmission (mechanics) for a car's transmission system''
In telecommunications, a transmission system is a system that transmits a signal from one place to another. The signal can be an electrical, optical or radio signal.
Some transmissi ...
s. In order to impress government regulators of this natural monopoly with the high quality of their service, Shewhart's first assignment was to improve the voice clarity of the carbon transmitters in the company's telephone handsets. Later he applied his statistical methods to the final installation of central station switching systems, then to factory production. When Shewhart joined the
Western Electric Company
The Western Electric Company was an American electrical engineering and manufacturing company officially founded in 1869. A wholly owned subsidiary of American Telephone & Telegraph for most of its lifespan, it served as the primary equipment m ...
Inspection Engineering Department at the
Hawthorne Works
The Hawthorne Works was a large factory complex of the Western Electric Company in Cicero, Illinois. Named after the original name of the town, Hawthorne, it opened in 1905 and operated until 1983. At its peak of operations, Hawthorne employed 4 ...
in 1918,
industrial quality was limited to inspecting finished products and removing defective items. That all changed on May 16, 1924. 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
Control charts is a graph used in production control to determine whether quality and manufacturing processes are being controlled under stable conditions. (ISO 7870-1)
The hourly status is arranged on the graph, and the occurrence of abnormalit ...
. 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's work pointed out the importance of reducing variation in a manufacturing process and the understanding that continual process-adjustment in reaction to non-conformance actually increased variation and degraded quality.
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. Dr. Shewhart created the basis for the control chart and the concept of a state of statistical control by carefully designed experiments. While Dr. Shewhart drew from pure mathematical statistical theories, he understood data from physical processes never produce a "
normal distribution
In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is
:
f(x) = \frac e^
The parameter \mu ...
curve" (a Gaussian distribution, also commonly called a "bell curve"). He discovered that observed variation in manufacturing data did not always behave the same way as data in nature (
Brownian motion
Brownian motion, or pedesis (from grc, πήδησις "leaping"), is the random motion of particles suspended in a medium (a liquid or a gas).
This pattern of motion typically consists of random fluctuations in a particle's position insi ...
of particles). Dr. Shewhart concluded that while every process displays variation, some processes display controlled variation that is natural to the process, while others display uncontrolled variation that is not present in the process causal system at all times.
Shewhart worked to advance the thinking at
Bell Telephone Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial research and scientific development company owned by mult ...
from their foundation in 1925 until his retirement in 1956, publishing a series of papers in the ''
Bell System Technical Journal''.
His work was summarized 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 International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, an ...
(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.
Later work
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 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
Clarence Irving Lewis
Clarence Irving Lewis (April 12, 1883 – February 3, 1964), usually cited as C. I. Lewis, was an American academic philosopher. He is considered the progenitor of modern modal logic and the founder of conceptual pragmatism. First a noted logic ...
, and this influenced his statistical practice. In particular, he had read Lewis' ''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
British Standards (BS) are the standards produced by the BSI Group which is incorporated under a royal charter and which is formally designated as the national standards body (NSB) for the UK. The BSI Group produces British Standards under the a ...
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:
# Data have no meaning apart from their context.
# Data contain both signal and noise. To be able to extract information, one must separate the signal from the noise within the data.
Shewhart visited India in 1947–1948 under the sponsorship of
P. C. Mahalanobis
Prasanta Chandra Mahalanobis OBE, FNA, FASc, FRS (29 June 1893– 28 June 1972) was an Indian scientist and statistician. He is best remembered for the Mahalanobis distance, a statistical measure, and for being one of the members of the first ...
of the
Indian Statistical Institute
Indian Statistical Institute (ISI) is a higher education and research institute which is recognized as an Institute of National Importance by the 1959 act of the Indian parliament. It grew out of the Statistical Laboratory set up by Prasanta ...
. He toured the country, held conferences and stimulated interest in statistical quality control among Indian industrialists.
He died at
Troy Hills, New Jersey in 1967.
Influence
In 1938 his work came to the attention of physicists
W. Edwards Deming
William Edwards Deming (October 14, 1900 – December 20, 1993) was an American engineer, statistician, professor, author, lecturer, and management consultant. Educated initially as an electrical engineer and later specializing in mathematical ...
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
Productivity is the efficiency of production of goods or services expressed by some measure. Measurements of productivity are often expressed as a ratio of an aggregate output to a single input or an aggregate input used in a production proces ...
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 that later became The
PDSA Cycle.
To celebrate his quasquicentennial (125th) birth anniversary, the journal ''Quality Technology and Quantitative Management'' () published a special issue in on "Advances in the Theory and Application of Statistical Process Control".
[Min Xie & Amitava Mukherjee (2017) "Quasquicentennial of birth of Shewhart", ''Quality Technology and Quantitative Management'' 14(4) ]
Achievements and honours
In his obituary for the
American Statistical Association
The American Statistical Association (ASA) is the main professional organization for statisticians and related professionals in the United States. It was founded in Boston, Massachusetts on November 27, 1839, and is the second oldest continuousl ...
, Deming wrote of Shewhart:
As a man, he was gentle, genteel, never ruffled, never off his dignity. He knew disappointment and frustration, through failure of many writers in mathematical statistics to understand his point of view.
He was founding editor of the ''Wiley Series in Mathematical Statistics'', a role that he maintained for twenty years, always championing
freedom of speech and confident to publish views at variance with his own.
His honours included:
* Founding member, fellow and president of the
Institute of Mathematical Statistics
The Institute of Mathematical Statistics is an international professional and scholarly society devoted to the development, dissemination, and application of statistics and probability. The Institute currently has about 4,000 members in all parts o ...
;
* Founding member, first honorary member and first
Shewhart Medal
The Shewhart Medal, named in honour of Walter A. Shewhart, is awarded annually by the American Society for Quality
The American Society for Quality (ASQ), formerly the American Society for Quality Control (ASQC), is a society of quality prof ...
ist of the
American Society for Quality
The American Society for Quality (ASQ), formerly the American Society for Quality Control (ASQC), is a society of quality professionals, with nearly 80,000 members.
History
ASQC was established on 16 February 1946 by 253 members in Milwaukee, ...
;
* Fellow and
President of the American Statistical Association
The president of the American Statistical Association is the head of the American Statistical Association (ASA). According to the association's bylaws, the president is an officer, and a member of the board of directors and of the executive commit ...
;
* Fellow of the
International Statistical Institute;
* Honorary fellow of the
Royal Statistical Society
The Royal Statistical Society (RSS) is an established statistical society. It has three main roles: a British learned society for statistics, a professional body for statisticians and a charity which promotes statistics for the public good.
...
;
*
Holley medal The Holley Medal is an award of ASME (the American Society of Mechanical Engineers) for "outstanding and unique act(s) of an engineering nature, accomplishing a noteworthy and timely public benefit by one or more individuals for a single achievemen ...
of the
American Society of Mechanical Engineers;
* Honorary Doctor of Science,
Indian Statistical Institute
Indian Statistical Institute (ISI) is a higher education and research institute which is recognized as an Institute of National Importance by the 1959 act of the Indian parliament. It grew out of the Statistical Laboratory set up by Prasanta ...
,
Calcutta
Kolkata (, or , ; also known as Calcutta , List of renamed places in India#West Bengal, the official name until 2001) is the Capital city, capital of the Indian States and union territories of India, state of West Bengal, on the eastern ba ...
.
Works
* 1917
A Study of the Accelerated Motion of Small Drops through a Viscous Medium Ph.D. dissertation via
Hathi Trust
HathiTrust Digital Library is a large-scale collaborative repository of digital content from research libraries including content digitized via Google Books and the Internet Archive digitization initiatives, as well as content digitized locally ...
* 1931
The Economic Control of Manufactured Product D. Van Nostrand Company via
Internet Archive
The Internet Archive is an American digital library with the stated mission of "universal access to all knowledge". It provides free public access to collections of digitized materials, including websites, software applications/games, music, ...
* 1939: (with
W. Edwards Deming
William Edwards Deming (October 14, 1900 – December 20, 1993) was an American engineer, statistician, professor, author, lecturer, and management consultant. Educated initially as an electrical engineer and later specializing in mathematical ...
Statistical Method from the viewpoint of Quality Control The Graduate School,
U. S. Department of Agriculture via Internet Archive
See also
*
Control chart
Control charts is a graph used in production control to determine whether quality and manufacturing processes are being controlled under stable conditions. (ISO 7870-1)
The hourly status is arranged on the graph, and the occurrence of abnormalit ...
*
Common cause and special cause (statistics)
Common and special causes are the two distinct origins of variation in a process, as defined in the statistical thinking and methods of Walter A. Shewhart and W. Edwards Deming. Briefly, "common causes", also called natural patterns, are the ...
*
Analytic and enumerative statistical studies
References
Further reading
* Bayart, D. (2001) Walter Andrew Shewhart, ''Statisticians of the Centuries'' (ed. C. C. Heyde and E. Seneta) pp. 398–401. New York: Springer.
* Bayart, D. (2005), "Economic control of quality of manufactured product" in
Grattan-Guinness, I., ed., ''Landmark Writings in Western Mathematics''. Elsevier: 926–35.
* 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)''
* Wheeler, Donald J. (1999). ''Understanding Variation: The Key to Managing Chaos'', 2nd ed. SPC Press, Inc. .
External links
Walter A. Shewhartat
American Society for Quality
The American Society for Quality (ASQ), formerly the American Society for Quality Control (ASQC), is a society of quality professionals, with nearly 80,000 members.
History
ASQC was established on 16 February 1946 by 253 members in Milwaukee, ...
Walter A. Shewharta
{{DEFAULTSORT:Shewhart, Walter Andrew
American industrial engineers
American statisticians
American business theorists
Quality
Quality experts
Scientists at Bell Labs
1891 births
1967 deaths
Presidents of the American Statistical Association
Presidents of the Institute of Mathematical Statistics
Fellows of the American Statistical Association
Fellows of the Econometric Society