Performance of Side Sensitive Group Runs Chart based on Exact and Random Process Shifts

<jats:p>A control chart is a crucial statistical tool that is typically used to monitor a process, inan effort to reduce variation. It is necessary to practically evaluate the overall performanceof a control chart. Evaluation reveals the effciency of a control chart to detect a processshift. This influences practitioners' decisions on the choice of a control chart. The usualpractice taken to evaluate the performance of a control chart is to use the average runlength (ARL). The assumption for using the ARL as a performance measure is that theshift size is known in advance. Determining the shift size can be restrictive, particularlyin the case practitioners do not have prior knowledge about the process. In view of this,the expected ARL (EARL) is employed as a performance measure for the random processmean shift. In this article, the overall performance of the side sensitive group runs (SSGR)chart is investigated in terms of EARL. Moreover, the optimal design for the SSGR chartbased on minimising the EARL is proposed.</jats:p>