Overview for Poisson Capability Analysis

Use Poisson Capability Analysis to determine whether the rate of defects per unit (DPU) meets customer requirements. Use this analysis when you count the defects on each item, and each item can have more than one defect. Using this analysis, you can do the following:

  • Determine whether the process is in control.
  • Estimate the defect rate per unit for each sample and across all samples (mean DPU).
  • Assess whether the DPU is stable.

For example, a textile manufacturer wants to analyze whether the defect rate for a fabric meets specifications. The manufacturer uses Poisson capability analysis to determine the number of defects per 100 yards of fabric and to assess whether the defect rate is stable.

Where to find this analysis

To perform Poisson capability analysis, choose Stat > Quality Tools > Capability Analysis > Poisson.

When to use an alternate analysis

If you can determine only whether each unit is defective or nondefective, use Binomial Capability Analysis to evaluate the percentage of defective items.