Quality Advisor

A free online reference for statistical process control, process capability analysis, measurement systems analysis, and control chart interpretation, and other quality metrics.

How do I compare the Cp/Pp and Cpk/Ppk?

Assume the original target is a Cpk or Ppk of 1.0

    If Cpk or Ppk is less than 1.0   If Cpk or Ppk is greater than 1.0
         
If Cp or Pp is less than 1.0   Variation in the process should be reduced.   Not mathematically possible. Check for an error in calculations.
         
If Cp or Pp is greater than 1.0   The process should be centered within its specifications.   Fine tune and improve the process continuously. Increase the Cpk target.

See also:
>> Cpk
>> Cp
>> Cr
>> Cpm
>> Ppk
>> Pp
>> Pr
>> Capability indices

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