过程能力指数Cp、Cpk与过程性能指数Pp、Ppk

摘要

Process capability index is the product quality evaluation tool used widely. Different process capability index has reasonable side, but also have shortcomings. Improper use may produce misleading. This paper studied the difference between the process capability index Cp,Cpk and process performance index Pp,Ppk. This paper also gave the relationship between the unqualified rate and the process capability index, process performance index and the corresponding estimation and confidence interval.%过程能力指数是一种广泛应用的产品质量评价工具。不同过程能力指数都有合理一面，但也都有不足之处，选用不当会产生误导。文章研究了过程能力指数Cp、Cpk与过程性能指数Pp、Ppk的差别及原因，并分别给出其与不合格率的关系和相应的估计和置信区间。