Data - Pareto Chart
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You can structure your data in one of two ways:

·    As one column of raw data, where each observation is an occurrence of a type of defect

·    As two column summary data, with one column of defect names and a corresponding column of non-negative values.

If you use text for the defects, each defect name can have as many as 72 characters.

Missing values

When you use Pareto Chart with raw data, Minitab counts the number of occurrences of each unique value in the column and displays a bar for each unique value. With text, a blank line is a missing value. For numeric data, a missing value is represented as an *. In either case, Minitab interprets the missing value as a unique value of the defect column. Pareto Chart includes a missing data bar as part of the plot. If you do not want a "missing" bar in the chart, use Data > Delete Rows or Data > Copy > Columns to Columns to remove rows with missing data.

When you use Pareto Chart with counts data, the defect label is matched up with the count in the same row of the frequencies column. If a value in the frequencies column is missing (*), Minitab removes that row of data. If a row in the names column is blank, Pareto Chart includes the data in the chart when count in that row is not missing. When the chart is displayed, no name appears for the defect.