Seven basic tools of quality: Difference between revisions

Revision as of 06:51, 15 October 2018

Revision as of 13:00, 22 October 2018

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*[[Stratified sampling|Stratification]] (alternately, [[flow chart]] or [[run chart]])

The designation arose in [[postwar Japan]], inspired by the [[Benkei#Seven Famous Weapons|seven famous weapons]] of [[Benkei]].{{sfn|Ishikawa|1990|p=98|ps=: "They were named the Seven QC Tools after the famous seven weapons of the Japanese [[Kamakura period|Kamakura-era]] warrior-priest Benkei which enabled Benkei to triumph in battle; so too, the Seven QC Tools, if used skillfully, will enable 95% of workplace problems to be solved. In other words, intermediate and advanced statistical tools are needed in about only 5% of cases."}} It was possibly introduced by [[Kaoru Ishikawa]] who in turn was influenced by a series of lectures [[W. Edwards Deming]] had given to Japanese engineers and scientists in 1950.<ref>{{cite web |last=Moore |first=Matthew |date=30 November 2007 |title=The Seven Basic Tools of Quality |url=http://www.improvementandinnovation.com/features/article/seven-basic-tools-quality/ |website= Improvementandinnovation.com |___location=London |archive-url=https://web.archive.org/web/20121019014101/http://www.improvementandinnovation.com/features/article/seven-basic-tools-quality/ |archive-date=19 October 2012 |access-date=18 May 2013}}</ref> At that time, companies that had set about training their workforces in [[quality control|statistical quality control]] found that the complexity of the subject intimidated the vast majoritymost of their workers and scaled back training to focus primarily on simpler methods which suffice for most quality-related issues.{{sfn|Ishikawa|1985|p=18|ps=: "It is true that statistical methods are effective, but we overemphasized their importance. As a result, people either feared or disliked quality control as something very difficult. We overeducated people by giving them sophisticated methods where, at that stage, simple methods would have sufficed."}} The [[Project Management Institute]] references the seven basic tools in ''[[A Guide to the Project Management Body of Knowledge]]'' as an example of a set of general tools useful for planning or controlling project quality.{{sfn|Project Management Institute|2013|pp=236–238}}

The seven basic tools stand in contrast to more advanced statistical methods such as [[survey sampling]], [[acceptance sampling]], [[statistical hypothesis testing]], [[design of experiments]], [[multivariate analysis]], and various methods developed in the field of [[operations research]].{{sfn|Ishikawa|1985|pp=198–199|ps=: "I divide statistical methods into the following three categories according to their level of difficulty. 1. Elementary Statistical Method (the so-called Seven Tools)&nbsp;... 2. Intermediate Statistical Method&nbsp;... 3. Advanced Statistical Method (using computers concurrently)".}}