New memory-type control charts for monitoring process mean and dispersion

Control chart is widely used to monitor the quality of products of industrial or business processes. Max-CUSUM and Max-EWMA are based on memory-type control charts that monitor the process mean and standard deviation simultaneously. This article introduces four new control charts that monitor the process mean and dispersion simultaneously. The proposed control charting schemes are compared with the existing counterparts including Max-EWMA, Max-CUSUM, SS-EWMA, and SS-CUSUM. A case study is presented for practical considerations using a real dataset