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Who really said it

Uncontrolled variation is the enemy of quality

Attributed to W. Edwards Deming 1900–1993 · American statistician and quality-management consultant
Attributed Rights unconfirmed

Widely credited to Deming, and squarely inside the subject he spent his life on — but no primary source pins the wording to him. The only citation anyone offers is a secondary one: a Wiley statistics textbook by Kang and Kvam, page 19, which credits Deming without naming a work. The Deming Institute’s own page-cited quote database does not list the line at all.

Last verified 7 Aug 2026 · how we verify · spot an error?

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Unconfirmed quote & credit

“Uncontrolled variation is the enemy of quality” Uncontrolled variation is the enemy of quality. — attributed to W. Edwards Deming (1900–1993). No primary source located: the citation usually offered is secondary, Kang and Kvam's Basic Statistical Tools for Improving Quality, p. 19, which credits Deming without naming a work of his. The Deming Institute's own page-cited quote database does not list the line. Via Quotle.info

Can you use it?

We couldn’t establish where this was first published, so there’s no rights status to give. Credit it as shown above — just don’t present it as public domain, and get permission for commercial or published reuse.

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In context

Evoking the world of W. Edwards Deming — American statistician and management consultant. Theme: "Uncontrolled variation is the enemy of quality". Atmospheric and restrained, cinematic directional light, a muted period-appropriate palette, fine grain and texture. Compose with generous empty space for the quote and a small credit line. No lettering in the image itself.

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Minimalist editorial slide for the quote "Uncontrolled variation is the enemy of quality". Clean background, a single muted accent color, generous negative space, subtle paper or linen texture, no literal illustration — let the words carry it. Reserve clear space for a serif quote and a small credit line. No lettering in the image itself.

Provenance

The source that isn’t there

Primary source
None located
Usual citation
Basic Statistical Tools for Improving Quality, p. 19
Year given
1980, with no work named
Deming Institute quote database
Does not list it

Uncontrolled variation is the enemy of quality. No primary source

There is no fuller context to show. The sentence has never been traced to a lecture, a seminar transcript, an article or a book of Deming’s — it circulates only as a free-standing epigraph.

W. Edwards Deming on Wikiquote

How we checked

  • Quote Investigator ↗ has never taken this one up. Site searches for “uncontrolled variation” and for “enemy of quality” both return no matches, so there is no specialist finding to defer to here.
  • Wikiquote’s Deming page ↗ does carry the line — but in its loose opening list, not in any of the sourced sections for Out of the Crisis, Some Theory of Sampling or The New Economics. Its note reads: “Attributed to Edward Deming (1980) in: Chang W. Kang, Paul H. Kvam (2012) Basic Statistical Tools for Improving Quality. p. 19.”
  • The Deming Institute cites its own quote database ↗ to the page — Out of the Crisis, Some Theory of Sampling, named seminars, dated interviews. Across all eleven pages of that database the words “enemy” and “uncontrolled” do not appear once.
  • Even the careful downstream users hedge. Health Catalyst’s piece on clinical variation says Deming “is credited as stating” ↗ the line, and points to the same textbook rather than to anything Deming wrote.

Because no work has been identified as the source, no copyright status can honestly be claimed for this wording. Worth noting either way: every book Deming published — from Statistical Adjustment of Data (1943) through Out of the Crisis and The New Economics for Industry, Government, Education (1993), as listed on Wikipedia ↗ — appeared well after 1930. If the line were ever traced to one of them, it would be in copyright, not public domain.

Rights status is our research, not legal advice — and copyright varies by country and edition. For commercial or published use, confirm with the rightsholder. See terms.

Fact-check

Credited everywhere, sourced nowhere

Nobody disputes that Deming spent his career on variation. What is missing is this sentence, in his voice, on a dated page. Every trail runs into the same short loop.

“Edward Deming (1980)” No work named

Wikiquote’s note ↗ renders his name as “Edward Deming,” gives a bare year, and then points not to Deming at all but to a Wiley statistics textbook by Chang W. Kang and Paul H. Kvam, page 19. No lecture, seminar or publication of that year is identified.

Explainers citing deming.org Dead end

A widely read process-management explainer quotes the line and hyperlinks it to the Deming Institute’s own “Knowledge of Variation” ↗ article as if that were the receipt. That article never uses the words “enemy” or “uncontrolled.”

Quote-collection sites No source

QuotePark reproduces the same Wikiquote line verbatim and then, in effect, admits the gap by asking readers to “help us to complete the source” ↗.

The honest ceiling is the one Health Catalyst reaches for: Deming “is credited as stating” ↗ it. Credited — not documented.

Context

He did teach this. Just not in these words.

Variation really was Deming’s subject. Building on Walter Shewhart’s control charts, he taught managers to separate ordinary, built-in variation from genuine special causes, and warned that reacting to the ordinary kind — tampering — only makes a system perform worse. He carried that teaching to Japan in his 1950 lectures on statistical product quality administration, and was still teaching it in four-day seminars four decades later.

So the slogan lands on the right target and still misses the shot. “Uncontrolled variation is the enemy of quality” compresses a distinction into a villain. Deming’s point was rarely that variation is an enemy; it was that variation is information, and that the real failure is not reading it.

The line sounds exactly like Deming. The footnote never arrives.

Read the full story

What Deming did put on the record, cited to the book: in The New Economics for Industry, Government, Education he asks, “What is the variation trying to tell us about a process, about the people in the process?” — recorded by Wikiquote ↗ under that book’s own heading, unlike the sentence on this page.

Understanding variation was never meant to stand alone. It is one of the four inseparable parts of Deming’s System of Profound Knowledge, alongside appreciation for a system, theory of knowledge and psychology, as the Deming Institute sets it out ↗. A one-line slogan about controlling variation is precisely the sort of tool-without-theory shortcut he spent his last years arguing against.

Explore

Filed under

More provenance-checked quotes on the same theme, each with its reuse status.

Work Success

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Dig deeper

Trusted places to keep pulling the thread — primary archives, fact-checks, and scholarship. We show how we used each one before you leave.

Wikiquote — W. Edwards Demingen.wikiquote.org

Carries the line in its unsourced opening list, with the lone citation to Kang and Kvam, p. 19 — and separately, the properly sourced quotes from each of Deming's books.
The W. Edwards Deming Institute — Quotesdeming.org

The Institute's own quote database, cited to page and seminar. Searchable and browsable; this line does not appear in it.
The Deming Institute — Knowledge of Variationdeming.org

What Deming actually taught about variation, as one of the four parts of the System of Profound Knowledge. Often cited as the source for this quote; it does not contain it.
Wikipedia — W. Edwards Demingen.wikipedia.org

Life dates, the 1950 Japan lectures, the 1980 NBC documentary, and the publication years of every book he wrote.
Open Library — Basic Statistical Tools for Improving Qualityopenlibrary.org

Catalogue record for the Kang and Kvam textbook that every trail to this quote eventually reaches.
Health Catalyst — Reducing Variation in Healthcarewww.healthcatalyst.com

An example of the line in wide professional use, and of the careful hedge: Deming 'is credited as stating' it.

About the man it is pinned on

Who was W. Edwards Deming?

W. Edwards Deming

1900–1993 · American statistician and management consultant

W. Edwards Deming was an American statistician who worked on sampling theory and statistical quality control before delivering his celebrated 1950 lectures on statistical product quality administration in Japan. He remained little known at home until NBC’s 1980 documentary If Japan Can... Why Can’t We? made him a management figure in the United States, after which he wrote Out of the Crisis and The New Economics for Industry, Government, Education and ran his four-day seminars until his death. His central teaching was the System of Profound Knowledge, in which understanding variation is one of four parts that cannot be separated from the others.

For writers & researchers

Cite this

How to cite this

No primary source located. The citation usually offered is secondary: Chang W. Kang and Paul H. Kvam, Basic Statistical Tools for Improving Quality (Hoboken, NJ: Wiley), 19 — given by Wikiquote as Kang and Kvam (2012), p. 19, crediting “Edward Deming (1980)” without naming a work of his.

This verification page

Quotle.info. “Who really said ‘Uncontrolled variation is the enemy of quality’?” Last verified 7 Aug 2026. https://quotle.info/who-said/uncontrolled-variation-is-the-enemy-of-quality/

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