An Evaluation of an Adaptive Generalized Likelihood Ratio Charts for Monitoring the Process Mean

When the objective is quick detection both small and large shifts in the process mean with normal distribution, the generalized likelihood ratio (GLR) control charts have better performance as compared to other control charts. Only the fixed parameters are used in Reynolds and Lou’s presented charts. According to the studies, using variable parameters, detect process shifts faster than fixed parameter control chart. In this paper, the performance of the adaptive GLR chart is evaluated. Based on the study, it is shown that the variable sampling size and sampling interval (VSSI) is more effective than the other adaptive GLR control charts in detecting small process mean shifts.