Talk:Control chart

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This article should not be merged. Control charts are a related but very clearly separate issue from the common and special causes from which they arise. -- Phil 20:39, 14 December 2005 (UTC)

[edit] Adding example pictures

I think this whole area of different statistical charting could really benefit from some example pictures of the relevant chart. Anyone care to add some example charts? Thanks --Evolve2k 08:05, 6 January 2006 (UTC)

I second that - I'm following the "The Pareto chart is one of the seven basic tools of quality control, which include the histogram, Pareto chart, check sheet, control chart, cause-and-effect diagram, flowchart, and scatter diagram. See Quality Management Glossary." to see all the charts, and most have them, but this does not, and from the description it takes some time to figure out what is displayed, and how.

[edit] Other control charts besides Shewhart ones

Shewhart charts are most common in control charting because of their relative simplicity (over other charts), and therefore are an excellent jumping off point. However, there are control charts (CUSUM, EWMA, and multivariate forms of CUSUM, EWMA, and Shewhart charts) which differ considerably from the basic rules being introduced here. The article in its present form is very much targeted to Shewhart control charts and overlooks the fact that there are other types of control charts which also test to see whether a process mean or variance has shifted. Significant amounts of information need to be added to this article, and I envision much of the content presently in this one moving to a new article titled Shewhart control charts. I am going to try to add a little bit to this article to get it started. --Statwizard 15:03, 23 March 2006 (UTC)

[edit] Factual error

Statement from article: "In 1938, Shewhart's innovation came to the attention of W. Edwards Deming, then working at the United States Department of Agriculture but about to become mathematical advisor to the United States Census Bureau."

"1925-26 Deming worked at the Hawthorne plant of the Western Electric Company on research with telephone transmitters, thus becoming aware of Shewhart's work." A Brief History of Dr. W. Edwards Deming British Deming Association SPC Press, Inc. 1992

I made that change, but I may have been hasty, since this source mentions nothing about that [1]. I suppose he could have done the research as part of his PhD degree, so I'll look for that. Spalding 18:55, 18 June 2006 (UTC)

This source [2] shows that he spent summers there, so I'll leave the edit. Spalding 19:01, 18 June 2006 (UTC)

The Deming Institute chronology is not intended to be comprehensive. Deming met Shewhart in 1927. The 1930s reference in the article is to the lectures Shewhart made at the USDA which led to Deming editing these for publication as Shewhart's 1939 book. Deming and Shewhart had a history before the lectures at UDSA. Leaders100 19:05, 18 June 2006 (UTC)