Statistical control charts for monitoring the mean of a stationary process

Recently, statistical process control (SPC) methodologies have been developed to accommodate autocorrelated data. A primary method to deal with autocorrelated data is the use of residual charts. Although this methodology has the advantage that it can be applied to any autocorrelated data, it needs time series modeling efforts. In addition, for a X residual chart, the detection capability is sometimes small compared to the X chart and EWMA chart. Zhang (1998) proposed the EWMAST chart, which is constructed by charting the EWMA statistic for stationary processes to monitor the process mean. The performance of the EWMAST chart, the X chart, the X residual chart, and other charts were compared in Zhang (1998). In this paper, comparisons are made among the EWMAST chart, the CUSUM residual chart, and EWMA residual chart as well as the X residual chart and X chart via the average run length.