A DYNAMIC-PROGRAMMING APPROACH TO THE ECONOMIC DESIGN OF X-CHARTS

Recent technological advances have rendered dynamic process control a viable alternative. A dynamic programming approach is proposed for the modeling and cost minimization of statistical process control activit ies. The decision parameters of the control chart are allowed to chang e dynamically as new information about the process becomes available. This general approach has been known as a theoretical possibility for many years, but its practical performance is explicitly investigated i n this paper. It is shown with numerical examples that the dynamic pro gramming solution can be much more economical than the conventional st atic solution with fixed control chart parameters. The substantial pot ential cost savings and the feasibility of a dynamic control procedure suggest that dynamic process control should replace standard statisti cal or economic design of control charts as the preferred method in au tomated production processes.