Demerit-Double Exponentially Weighted Moving Average Control Chart with Fast Initial Response

Abstract

Defects of complex products such as automobiles, computers, home appliances etc. are not found to be only in one type and the importance of such defects by types are not always same. For systems in which defects with such different importance by various types exist, the process is generally used the Demerit control charts. This study suggested the Demerit-Double EWMA control chart which integrates the Double EWMA (exponentially weighted moving average) technique with the classical Demerit control chart and evaluates its performance. As a method of rapidly detecting an off-target process at start-up, the fast initial response (FIR) features were additionally applied to the Demerit-Double EWMA control chart.