Economic Statistical Control-Chart Designs With an Application to and R Charts

Control charts are the primary tools of statistical process control. These charts may be designed by using a simple rule suggested by Shewhart, by a statistical criterion, or by an economic criterion. Each method has its advantages and disadvantages. In this article, I place statistical constraints on economic models to provide designs that meet industry's demand for lowprocess variability and long-term product quality. This constrained economic model yields a design I call an economic statistical design. The model can be readily adapted to design ant Shewhart-type control chart. In this article, I illustrate its use in the joint design of an chart and an R chart.