A Review and Evaluation of Statistical Process Control Methods in Monitoring Process Mean and Variance Simultaneously

In this paper, first the available single charting methods, which have been proposed to detect simultaneous shifts in a single process meanand variance, are reviewed. Then, by designing proper simulation studies these methods are evaluated in terms of in-control and out-ofcontrolaverage run length criteria (ARL). The results of these simulation experiments show that the EWMA and EWMS methods are quitecapable to detect large shifts in the means and variances. However, while the two EWMV procedures under study do not perform well, theMax-Min EWMA and Max-EWMA perform very well in all scenarios of mean and variance shifts

Keywords:

Statistical Quality Control , Control Chart , Simultaneous Control of Mean and Variance