seven basic tools of quality

The seven tools are:{{sfn|Tague|2005|p=15}}{{harvnb|Ishikawa|1985|p=198|ps=: "Elementary Statistical Method (the so-called Seven Tools) 1. Pareto chart: The principle of vital few; trivial many 2. Cause and effect diagram (This is not precisely a statistical technique) 3. Stratification 4. Check sheet 5. Histogram. 6. Scatter diagram (analysis of correlation through determination of median; in some instances, use of binomial probability paper) 7. Graph and control chart (Shewhart control chart)".}}{{sfn|Imai|1986|pp=239–240|ps=: "The seven statistical tools used for such analytical problem-solving are: 1. Pareto diagrams ... 2. Cause-and-effect diagrams ... 3. Histograms ... 4. Control charts ... 5. Scatter diagrams ... 6. Graphs ... 7. Checksheets."}}

1. Cause-and-effect diagram (also known as the "fishbone diagram" or Ishikawa diagram)
2. Check sheet
3. Control chart
4. Histogram
5. Pareto chart
6. Scatter diagram
7. Stratification (alternatively, flow chart or run chart)

The designation arose in postwar Japan, inspired by the 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-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.{{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}} At that time, companies that had set about training their workforces in statistical quality control found that the complexity of the subject intimidated most 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) ... 2. Intermediate Statistical Method ... 3. Advanced Statistical Method (using computers concurrently)".}}

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{{refbegin|35em|indent=yes}}

• {{cite book |last1=Duffy |first1=Grace L. |last2=Furterer |first2=Sandra L. |title=The ASQ Certified Quality Improvement Associate Handbook |date=8 June 2020 |publisher=Quality Press |isbn=978-1-951058-13-5 |language=en |chapter=Chapter 9. Improvement Tools}}
• {{cite book

|last=Imai

|first=Masaaki

|author-link=Masaaki Imai

|year=1986

|title=Kaizen (Ky'zen): The Key to Japan's Competitive Success

|url=https://archive.org/details/kaizenkyzenkey00imai

|url-access=registration

|edition=1st

|location=New York

|publisher=Random House

|isbn=978-0-394-55186-9

}}

• {{cite book

|last=Ishikawa

|first=Kaoru

|author-link=Kaoru Ishikawa

|year=1985

|title=What Is Total Quality Control? The Japanese Way

|translator-last=Lu

|translator-first=David J.

|edition=1st

|location=Englewood Cliffs, New Jersey

|publisher=Prentice-Hall

|isbn=978-0-13-952433-2

|url-access=registration

|url=https://archive.org/details/whatistotalquali00ishi

}}

• {{cite book

|last=Ishikawa

|first=Kaoru

|author-link=Kaoru Ishikawa

|author-mask={{long dash}}

|year=1990

|title=Introduction to Quality Control

|edition=1st

|location=Tokyo

|publisher=3A Corp

|isbn=978-4-906224-61-6

}}

• {{cite book

|last=Montgomery

|first=Douglas

|year=2005

|title=Introduction to Statistical Quality Control

|location=Hoboken, New Jersey

|publisher=John Wiley & Sons

|isbn=978-0-471-65631-9

}}

• {{cite book

|author=Project Management Institute

|author-link=Project Management Institute

|year=2013

|title=A Guide to the Project Management Body of Knowledge

|edition=5th

|location=Newtown Square, Pennsylvania

|publisher=Project Management Institute

|isbn=978-1-935589-67-9

}}

• {{cite book

|last=Tague

|first=Nancy R.

|year=2005

|title=The Quality Toolbox

|edition=2nd

|location=Milwaukee, Wisconsin

|publisher=ASQ Quality Press

|isbn=978-1-62198-045-2

|url-access=registration

|url=https://archive.org/details/projectmanagersc0000benz

}}

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{{Quality Tools}}

{{Authority control}}

Category:Quality control tools

Category:Quality