Adaptive risk adjusted exponentially weighted moving average control chart based on accelerated failure time regression

Control charts play an effective role in monitoring and controlling the performance of health care. It helps to determine the strategy to improve the process and identify the causes of variations. In recent years, the risk adjusted memory type control charts have received reasonable attention in monitoring surgical outcomes. In this research, we used the concept of an adaptive exponentially weighted moving average (AEWMA) control chart and proposed a new adaptive risk adjusted exponentially weighted moving average (ARAEWMA) control chart by using the accelerated failure time (AFT) regression. A real data set of the cardiac surgery patients is used for analysis and the patient condition is counted by personnet score method. The proposed ARAEWMA control chart is fitted by using the AFT model and run length profiles are computed at different shifts. The proposed ARAEWMA chart is better in shift detection and showed efficient results than the risk adjusted exponentially weighted moving average control chart.