- Pareto chart
A Pareto chart is a special type of bar chart where "the values being plotted are arranged in descending order." The graph is accompanied by a line graph which shows the cumulative totals of each category, left to right. The chart is named after
Vilfredo Pareto , and its use inquality assurance was popularized byJoseph M. Juran andKaoru Ishikawa .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 , andscatter diagram . Seeglossary of quality management . These charts can be generated inMicrosoft Office orOpenOffice . It is possible to use one of the software tools or one of free "online quality chart generators" as well.Typically on the left vertical axis is frequency of occurrence, but it can alternatively represent cost or other important unit of measure. The right vertical axis is the cumulative percentage of the total number of occurrences, total cost, or total of the particular unit of measure. The purpose is to highlight the most important among a (typically large) set of factors. In
quality control , the Pareto chart often represents the most common sources of defects, the highest occurring type of defect, or the most frequent reasons for customer complaints, etc.The Pareto chart was developed to illustrate the
80-20 Rule fact|date= June 2008 — that 80 percent of the problems stem from 20 percent of the various causes.External links
* [http://www.isixsigma.com/library/content/c010527a.asp Brief discussion, with example]
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