Check sheet
Control chart
Histogram
Scatter diagram
Flow chart
Run chart
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A histogram is an approximate representation of the distribution of numerical data. The term was first introduced by Karl Pearson. To construct a histogram, the first step is to "bin" the range of values—that is, divide the entire range of values into a series of intervals—and then count how many values fall into each interval. The bins are usually specified as consecutive, non-overlapping intervals of a variable. The bins (intervals) must be adjacent and are often of equal size.
Ishikawa diagrams are causal diagrams created by Kaoru Ishikawa that show the potential causes of a specific event.
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Kaoru Ishikawa was a Japanese organizational theorist and a professor in the engineering faculty at the University of Tokyo noted for his quality management innovations. He is considered a key figure in the development of quality initiatives in Japan, particularly the quality circle. He is best known outside Japan for the Ishikawa or cause and effect diagram, often used in the analysis of industrial processes.
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A plot is a graphical technique for representing a data set, usually as a graph showing the relationship between two or more variables. The plot can be drawn by hand or by a computer. In the past, sometimes mechanical or electronic plotters were used. Graphs are a visual representation of the relationship between variables, which are very useful for humans who can then quickly derive an understanding which may not have come from lists of values. Given a scale or ruler, graphs can also be used to read off the value of an unknown variable plotted as a function of a known one, but this can also be done with data presented in tabular form. Graphs of functions are used in mathematics, sciences, engineering, technology, finance, and other areas.
Masaaki Imai is a Japanese organizational theorist and management consultant, known for his work on quality management, specifically on Kaizen.
References
Footnotes
- ↑ Montgomery 2005, p. 148.
- ↑ Ishikawa 1985, p. 198: "From my past experience as much as ninety percent of all problems within a company can be solved by means of these tools."
- ↑ Tague 2005, p. 15.
- ↑ Ishikawa 1985 , p. 198: "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)".
- ↑ Imai 1986, pp. 239–240: "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."
- ↑ Ishikawa 1990, p. 98: "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."
- ↑ Moore, Matthew (30 November 2007). "The Seven Basic Tools of Quality". Improvementandinnovation.com. London. Archived from the original on 19 October 2012. Retrieved 18 May 2013.
- ↑ Ishikawa 1985, p. 18: "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."
- ↑ Project Management Institute 2013, pp. 236–238.
- ↑ Ishikawa 1985, pp. 198–199: "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)".
Bibliography
- Imai, Masaaki (1986). Kaizen (Ky'zen): The Key to Japan's Competitive Success (1st ed.). New York: Random House. ISBN 978-0-394-55186-9.
- Ishikawa, Kaoru (1985). What Is Total Quality Control? The Japanese Way . Translated by Lu, David J. (1st ed.). Englewood Cliffs, New Jersey: Prentice-Hall. ISBN 978-0-13-952433-2.
- ——— (1990). Introduction to Quality Control (1st ed.). Tokyo: 3A Corp. ISBN 978-4-906224-61-6.
- Montgomery, Douglas (2005). Introduction to Statistical Quality Control. Hoboken, New Jersey: John Wiley & Sons. ISBN 978-0-471-65631-9.
- Project Management Institute (2013). A Guide to the Project Management Body of Knowledge (5th ed.). Newtown Square, Pennsylvania: Project Management Institute. ISBN 978-1-935589-67-9.
- Tague, Nancy R. (2005). The Quality Toolbox (2nd ed.). Milwaukee, Wisconsin: ASQ Quality Press. ISBN 978-1-62198-045-2.