Estimation of capability index based on bootstrap method

A process capability index C-pmk is recently proposed to measure the degree of process capability of a system. C-pmk is a generalized version of the existing indices C-p, C-pk, and C-pm, which have been studied extensively in the last few years. In this paper, we present the estimators of C-pmk and derive its asymptotic distribution. We also utilize the asymptotic variance of the estimator of C-pmk to derive the two-sided confidence interval for C-pmk based on a percentile-t bootstrap method. Our new confidence intervals are shown to outperform the ones based on the percentile and standard bootstrap method by simulation. Copyright (C) 1996 Elsevier Science Ltd