Bi-objective Economic statistical design of the joint Xbar and S charts incorporating Taguchi loss function

In this research, a bi-objective model for the economic-statistical design of the X-bar and S control charts is proposed. The model minimizes out-of-control average time to signal as well as minimizing mean hourly loss-cost where it incorporates the Taguchi loss function. A statistical constraint is considered in the model to achieve the desired in-control time to signal. A non-dominated sorting genetic algorithm is developed to obtain the pareto optimal scheme of the control chart. Sensitivity analysis and comparison study with traditional economic models presents that the proposed bi-objective design of X-bar and S control chart ensures a better approach to improve the quality system and increase the plans ease of use.