Calculation

Process Capability Cp and Cpk

Created on · spc-capability

Compares measurement data against specification limits and separates short-term from total variation.

Measured values

Lower specification limit

Upper specification limit

How to use the result

Check the definition of the dimension and datum conditions on the drawing. The calculator does not replace inspection of the specific part.

σ_short = MR̄ / 1,128Cp = (USL − LSL) / (6σ_short)Cpk = min(USL − mean, mean − LSL) / (3σ_short)

Sources: https://www.itl.nist.gov/div898/handbook/pmc/section3/pmc322.htm