A critical note on the exponentiated EWMA chart
摘要
In this short note, we reevaluate the run-length performance of the EWMA and exponentiated EWMA (Exp-EWMA) charts using the conditional expected delay metric. It is found that the enhancements offered by the Exp-EWMA chart over the EWMA chart in the zero-state setup are marginal. Given its simplicity in implementation and its ability to encompass the functionality of the Exp-EWMA chart in detecting delayed shifts in the process mean, the EWMA chart remains the preferred choice over the Exp-EWMA chart.