Operations Research, Systems Engineering and Industrial Engineering Commons^™

Revisiting The One-Sided Ewma Control Chart Design, Duy Anh Duong-Tran

Masters Theses

Over the past half-century, Exponential Weighted Moving Average (EWMA) control charts have been widely used in Statistical Process Control to detect small and persistent process shifts. In theory, EWMA control limits monotonically increase over time to account for the continual growth of the EWMA statistic’s variance. These control limits are often assumed constant and are set to their respective asymptotic limits. While not theoretically correct, this simplifies the process of applying and analyzing the EWMA control chart while having little effect on the chart’s performance. One-Sided EWMA charts are often implemented when it is only desirable to detect shifts in …