Process capability indices have been used in the manufacturing industry to provide quantitative measures on process potential and performance. The formulae for these indices are easy to understand and straightforward to apply. But, since sample data must be collected in order to calculate these...

For non‐normal Pearsonian processes, Clements proposed a method for calculating estimators of the two basic process capability indices C p and C pk . Pearn and Kotz applied Clements’ method to obtain estimators for the other two more advanced process capability indices C pm and C pmk . Their...