A 2-stage cumulative quantity control chart

In this research, the authors use the Gamma random variable to construct a 2-stage cumulative quantity control chart (CQC chart) for monitoring Poisson processes. Such a, 2-stage control chart provides a compromise between the discriminating power and the average quantity inspected in detecting shift of the process nonconforming rate. This paper proves a theoretical result that compares the discriminating power of three types of CQC charts and optimizes these charts from an economic point of view.