Performance of customized control charts to detect process disturbances

In this paper we demonstrate the use of control charts based on orthogonal contrasts for a semiconductor manufacturing process. The statistical performance of individuals control charts based on these contrasts and their exponentially weighted moving average counterparts is compared to that of the traditional approach. Contrast‐based charts have superior detection capabilities than the traditional approach when targeted at specific process disturbances. Copyright © 2001 John Wiley & Sons, Ltd.