Designing an Economic EWMA Control Chart for Monitoring Attributes under Statistical Constraints

Abstract

This research discusses economic-statistical design of the exponentially weighted moving average (EWMA) control chart. Based on Duncan’s model, an optimization approach is proposed for designing the EWMA chart to reduce the expected total cost (ETC) under statistical constrains. The developed EWMA chart is thereafter compared with the traditional EWMA chart so that its superiority can be evaluated. The study shows that the proposed EWMA chart outperforms the conventional EWMA chart for monitoring defectives.