ECONOMIC-STATISTICAL DESIGN OF DOUBLE SAMPLING S CONTROL CHART

In this study, an economic-statistical design of the double sampling (DS) s chart is investigated. The optimal design parameters of the DS s chart are obtained by minimizing the cost subject to statistical constraints. The effectiveness of the DS s chart is evaluated by comparing its minimized cost against the cost of the Shewhart s chart. The comparison demonstrates the superiority of the DS s chart over the Shewhart s chart, where the DS s chart is economically superior to the Shewhart s chart. Sensitivity analyses are performed to investigate the effect of the cost parameters, process parameters and statistical properties on the design parameters, as well as the corresponding in-control average time to signal, out-of-control average time to signal and cost.