So in this post I will show you how to calculate Ppk using Minitab’s default settings when the subgroup size is greater than 1. Then, in my next post, I’ll show you how to calculate Cpk. Default Capability Methods For data that follow the normal distribution, we use a Normal ...
虽然Cpk 和 Ppk 是流程能力的最常用指标,但它们仅度量流程的执行情况与最接近过程均值的规格限的关系。因此,它们仅评估过程曲线的一侧,但不直接指示此流程在过程曲线另一侧的执行情况。 要清楚了解流程在过程曲线两侧的工作,您可以使用其他指标,例如 PPM。PPM<LSL 表示不合格部件的数量小于规格下限。PPM > ...
Since Cpk is the lesser of the two resulting values, Cpk is 0.83. That matches the Cpk value in Minitab’s capability output: As long as you're using Minitab, you won't need to calculate Ppk and Cpk by hand. But I hope seeing the calculations Minitab uses to get these capability i...