Track: Statistical Process Control

Abstract

This paper puts forward the concept of optimzing the Exponentially Weighted Moving Average (EWMA) control chart for effective monitoring of the increasing shifts in defective rate in food packaging. Optimizing the EWMA chart mainly aims at enhancing the product quality and the customers' contentment, along with reducing both production costs and waste. The Average Number of Defectives (AND) is used as an overall performance metric for guaranteeing the highest detection power of th optimal EWMA chart with respect to various sizes of shifts. Records of the packaging defects were collected from a food company in order to illustrate the implementation of the proposed optimal EWMA chart. The optimal EWMA chart is compared with the optimal NP chart and the results of this comparative study reveal that the former exceeds the latter by 69% in terms of AND.