Estimating Process Capability Index C_(PM) Using a Bootstrap Sequential Sampling Procedure

摘要

Construction of a confidence interval for process capability index C_(PM) is often based on a normal approximation with fixed sample size. In this article, we describe a different approach in constructing a fixed-width confidence interval for process capability index C_(PM) with a preassigned accuracy by using a combination of bootstrap and sequential sampling schemes. The optimal sample size required to achieve a preassigned confidence level is obtained using both two-stage and modified two-stage sequential procedures. The procedure developed is also validated using an extensive simulation study.