On designing Maxwell CUSUM control chart: an efficient way to monitor failure rates in boring processes

Abstract

The ordinary CUSUM chart is based on normality assumption. But in real-life phenomenon such as monitoring of lifetime variable, this assumption is not always valid. Hence, a variant of the CUSUM chart, the VCUSUM chart, has been constructed to monitor small shift in a process that is based on a Maxwell distribution. The performance of the chart has been checked by studying the run length properties and it was found to perform better for small shifts as compared to Shewhart type V chart for Maxwell parameter. Finally, a real-life application is presented to monitor the failure rate of a vertical boring machine.