Capability assessment for processes with multiple characteristics: A generalization of the popular index Cpk

The generalized yield index CT pk establishes the relationship between the manufacturing specifications and the actual process performance, which provides a lower bound on process yield for two-sided processes with multiple characteristics. The results attended are very practical for industrial application. In this article, we extended the results in cases with one-sided specification and multiple characteristics. The generalized index CT PU was considered, and the asymptotic distribution of the natural estimator ĈPU T was developed. Then, we derived the lower confidence bounds as well as the critical values of indexCT PU. We not only provided some tables but also presented an application example. Copyright © 2012 John Wiley & Sons, Ltd.