Adaptive Phase II Nonparametric EWMA Control Chart with Variable Sampling Interval

In this paper, we provide an adaptive Phase II nonparametric exponentially weighed moving average control chart using variable sampling interval for detecting a range of shifts in the location parameter. This chart is an adaptive one and has a variable sampling interval, which makes it more efficient. Further, it is a self‐starting scheme and thus can be used to monitor processes at the start‐up stages. The choice of the chart parameters is studied, and a simulation study demonstrates that the proposed control chart not only performs robustly for different distributions, but also efficiently detects various magnitudes of shifts. An illustrative example is given to introduce the implementation of this proposed control chart.