A mixed nonparametric control chart for efficient process monitoring

In this paper, we propose a nonparametric mixed control chart using exponentially weighted moving average and cumulative sum (statistics for efficient monitoring of quality characteristic). The proposed control chart, namely NPMEC chart, proceeds in two steps. The necessary constants required in the construction of the proposed mixed chart are determined. The performance evaluation of the proposed chart in terms of run length characteristic is also considered. The comparison of this new mixed chart with the existing charts is also done here. The comparison reveals that the NPMEC chart performs efficiently for detecting a moderate to larger shift and almost reacts similarly or a bit late towards detecting the smaller shifts as compared to its counterparts.