A new process monitoring control chart

Abstract

Using a single chart to monitor simultaneously the process mean and variability if found would cut down the time and effort. Some researches have been done in finding such charts. Moreover, some researches have showed that the adaptive control charts could detect process shifts faster than the traditional Shewhart charts. A much easier loss chart with variable design parameters is proposed here to monitor both the deviation from the process target and the shift in process variability. Furthermore, a more efficient optimal variable design parameters loss chart is proposed and performs better than the loss chart with fixed design parameters and the joint X̄ and S charts.