Cpk

Index which reflects the relative probability of making a part outside of defined specification limits -- i.e. the expected level of defects for a given part. In PlantStar Panorama, the Cpk is calculated only over the range of subgroups that are currently displayed on a window's graph. The calculation is:

Min ((X-bar Mean - Lower Spec) , (Upper Spec - X-bar Mean))
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3* Standard Deviation