A Modified Statistical Design Model of Double Sampling (X)over-bar Control Chart

The double sampling (DS) control chart can efficaciously reduce sample sizes and increase performance of process monitoring. Hsu [Int j. prod. res., vol. 42, no. 5, pp. 1043-1047] mentioned that the statistical design model of DS (X) over bar control chart could merely minimize sample sizes during in-control process monitoring but fail to decrease sample sizes during detection of process shifts. In this study, with minimization of sample sizes for both in-control process and out-of-control process, a multi-objective programming method and genetic algorithm are proposed for statistical designs of DS (X) over bar control chart. In comparison with both statistical design models, it is quite obvious that our model can effectively lower sample sizes of two process situations.