A process incapability index

Abstract

Introduces a process capability index which indicates the incapability of a process to meet its specifications. This incapability index is obtained by a transformation of the C*pmindex, and it is more informative than C*pm. This transformation allows one to separate information concerning the process variation from information concerning the departure from the process target. As a result, departure from the process target can be assessed without process variation, and vice versa. Presents a number of practical estimators and confidence bounds (intervals).