Process Capability Indices Based on Skewed Possibility Distributions for Drilling Operations

Process capability indices play an important role in the process control since they help determine if a manufacturing process is suitable. They are unitless and defined as the ratio of specification conformance to the natural variability of a process. This variability is generally determined by using a normal probability distribution or in a few cases by Pearson or Burr systems of distribution. This paper investigates the use of skewed possibility distributions to model data variability. Bridges with existing approaches and new results are presented and illustrated on drilling operations.