Process capability

This article is about the quantifiable measure of a process. For software process capability, see Capability Maturity Model and ISO/IEC 15504.

The process capability is a measurable property of a process to the specification, expressed as a process capability index (e.g., Cpk or Cpm) or as a process performance index (e.g., Ppk or Ppm). The output of this measurement is often illustrated by a histogram and calculations that predict how many parts will be produced out of specification (OOS).

Two parts of process capability are:

  1. Measure the variability of the output of a process, and
  2. Compare that variability with a proposed specification or product tolerance