Letter to the editor the asymptotic distribution of the process capability index cpmk
In theorem 3.1 of Chen and Hsu (1995) an expressin for an upper confidence bound for Cpmk in the case when µ = M and so Cpmk = Cpm, is given as a multiple of Cpm. However, if the value µ = M known then it would be more reasonable to use the estimator obtained by replacing Xn by M.