Process Capability Index (Cp, Cpk)

The Process Capability Index (Cp) and (Cpk) are tools that measure how well a manufacturing process produces items within specified limits. Cp compares the spread of the process variation to the allowed tolerance; if Cp is high, the process is capable of fitting within limits. Cpk considers how centered the process is within those limits; a high Cpk indicates the process not only produces within tolerances but is also well-centered. Together, they assess whether a process consistently produces quality products and help identify areas for improvement.