> Lean Terms & Definitions
> Cp Process Capability
CP PROCESS CAPABILITY
Cp Process capability is the measured, inherent
reproducibility of the product turned out by a process. The most
widely adopted formula for process capability (Cp) is:
Process Capability (Cp) = 6? = Total Tolerance ? 6
Where ? = the standard deviation of the process under a state of
statistical control. One of the most commonly used measures for
process capability is process capability index (Cpk) is:
Cpk = Lesser of Cpu or Cpl
Cpu = (Upper Specification - Process Mean) ? 3?
Cpl = (Process Mean - Lower Specification) ? 3?
Interpretation of the index is generally as follows:
Cpk > 1.33 more than adequate
Cpk < 1.33 but > 1.00 adequate, but must be monitored as
it approaches 1.00
Cpk <1.00 but > 0.67 not adequate for job.
Cpk < 0.67 totally inadequate.
Learn more about Six Sigma Overview
and TCA Six Sigma Program.