过程能力指数和性能指数的若干问题研究

Study on process capability index and process performance index

通过对过程能力指数Cpk和过程性能指数Ppk的定义及计算过程的研究,分析Cpk和Ppk的不同,对常用的过程能力指数做出了较为全面的解释,澄清了“Cpk为零就是合格品率为零的”错误观点,并且给出了两种指数的使用范围.

Based on studying the definition and calculation method of Cpk and Ppk, the paper analyzes the difference between Cpk and Ppk and provideds a detailed understanding of process capability. It clarifies that “if Cpk = 0, disqualification rate is also zero” is a wrong idea and presents the application scope of the two indices.