An economic statistical design model for a ππ control chart which uses a variable sample size feature is developed in this paper. The determination of the optimal design requires the computation of the average number of samples (ANS) and the average number of items (ANI) taken when the process is in control or out of control. In this article, these characteristics have been calculated via a new approach. Application of the proposed πππ ππcontrol chart design is demonstrated through a numerical example.
