Poisson capability analysis to determine whether
the rate of defects per unit (DPU) meets customer
Use this analysis when you count the defects on each item, and
each item can have more than one defect.
For example, a textile manufacturer uses a
Poisson capability analysis to determine the number
of defects per 100 yards of fabric and to assess whether the defect rate is
stable. To see an example, go to
Example of Poisson Capability Analysis.
You must be able to count the number of defects on each item or unit. Try
to collect at least 25 subgroups. If you do not collect a sufficient amount of
data over a long enough period of time, the data may not accurately represent
different sources of process variation and the estimates may not indicate the
true capability of your process. For details, go to
Data considerations for Poisson Capability