製程能力指標是製程品質特性相關分配之參數的函數。製程能力指標Cp, Cpk及Cpm 已經廣泛地被製造業用來評估製程是否達到製造規格或品質的要求，是一個容易運用的績效評估工具。對於製程能力指標的研究大多數集中於點估計，由於抽樣誤差的忽略易導致指標估計值的不可靠。在本文中，針對這些指標提供另一種簡易方便可靠的方法以評估製程的績效。 A process capability index is a function of some parameters of some involved distribution and it specifies a quality characteristic. The process capability indices Cp ;Cpk and Cpm have been used in manufacturing industries to provide a quantitative measurement of the potential and performance of the manufacturing. These indices are easy to apply. Most studied on process capability indices are focusing on point estimates; which may result in misleading assessments of process performance. In this paper; we consider Cp ; Cpk and Cpm ; and develop a simple and convenient procedure
for decision making in assessing process capability.