Capability Analysis (Poisson Distribution) Results - Advanced Tab

Select the Advanced tab in the Capability analysis (Poisson distribution) results dialog box to access options to create individual summary spreadsheets and graphs, which are summarized into a single graph document via the Observed Capability Summary option on the Quick tab.

U Chart

Click this button to create a u-chart of the percentage or rates. See also the u-chart topic in the Glossary. In general, this chart is useful to determine that, overall, the process is (or is not) in control.

Defect Rate

Click this button to create a scatterplot

• Of defect rates; or percentages vs. sample sizes if unequal sample sizes were encountered
• A scatterplot of observed defects vs. expected defects if fixed sample sizes were specified.

Cumulative DPU

Click this button to create a chart of the cumulative DPU (defects per unit) across samples.

This chart is useful to determine if a sufficient number of samples were taken to estimate a stable value of the percent defective, or the defect rate.

This plot is useful to determine if the chosen distribution is appropriate for the respective data, and also enables you to determine the quality of the process relative to the specified upper specification limit.

Distribution of DPU

Click this button to create a histogram (distribution) of the defects per unit.

See also Example 10: Capability Analysis (Binomial), Process Analysis - Capability Analysis Binomial and Poisson, and Capability Analysis - Binomial and Poisson - Computational Details.