Sensitivity improvement method of CV control chart

摘要

The response of the CV control chart remains less sensitive for smaller shifts in process at it uses information of current lot only. The CV-EWMA control chart and the CV-DEWMA control chart were developed to control processes with higher sensitivity to small shifts of CV. In this paper, we propose an FIR (Fast initial response) CV-DEWMA control chart to improve the sensitivity of a CV-DEWMA control chart at process start-up or out-of-control process. Moreover, we show the results of the performance study of FIR CV-DEWMA control chart by comparing with CV-DEWMA control chart.