Pareto Chartoverview how to examples data see also
Pareto ChartStat > Quality Tools > Pareto Chart
Pareto charts are a type of bar chart in which the horizontal axis represents attributes of interest, rather than a continuous scale. These attributes are often "defects." By ordering the bars from largest to smallest, a Pareto chart can help you determine which of the defects comprise the "vital few" and which are the "trivial many." A cumulative percentage line helps you judge the added contribution of each category. Pareto charts can help to focus improvement efforts on areas where the largest gains can be made.
Minitab generates the Pareto chart based on either a single column of raw attribute data or summary data consisting of a column of labels and a corresponding column of values. Pareto chart can draw one chart for all your data (the default), or separate charts for groups within your data.
Defects or attribute data in: Do one of the following:
In both cases, the column can be either text or numeric data, so you can use names or numeric codes to represent the defects. If you use text, each defect name can have up to 72 characters, although Minitab uses only the first 15; be sure defect names are distinct within the first 15 characters.
Frequencies in (optional): For summary data only, enter the column containing non-negative values corresponding to the defect names or codes specified in Defects or attribute data in.
BY variable in (optional): Enter the column containing the indicator variable you want to use to designate which group each observation belongs in. This column must be the same length as the Defects or attribute data in column and can contain text or numeric data. Numeric data does not need to be integers. The maximum number of indicator variable levels is 100.
All on one graph, same ordering of bars: Choose to display a matrix of Pareto diagrams, one for each group, using the same ordering of bars on each chart. The order of the bars are determined by the overall data set. All groups will have their bars represented in the same order, which in most cases will mean that bars in all groups will not be in Pareto order.
One group per graph, same ordering of bars: Choose to draw a separate full-page Pareto diagram for each group using the same ordering of bars on each page. The order of the bars in all of the Pareto diagrams is determined by the first group. All other groups will have their bars represented in the same order as the first group, which in most cases will mean that bars in subsequent groups will not be in Pareto order. However, this can be useful for comparing importance of categories relative to a baseline, which is the first group. Each chart displays in a separate Graph window.
One group per graph, independent ordering of bars: Choose to order the bars in each group's Pareto diagram independently of all other groups. In other words, the bars in each Pareto diagram will be in Pareto order, which means that in most cases the order will be different between groups. Each chart displays in a separate Graph window.
Combine remaining defects into one category after this percent: Choose when you want to specify a percent after which the rest of the defects will be combined into one category. Enter the cumulative percentage for which you want to generate bars. Minitab generates bars for defects until the cumulative percentage surpasses the % specified, then groups the remaining defects into a bar labeled "Others." The default cumulative percentage is set at 95%.
Do not combine: Choose when you don't want to combine defects into an "Others" category.