Abstract
Primarily, three types of control charts are employed to observe the disturbances in the process parameters. The large shifts are detected efficiently by Shewhart's control chart, whereas for small and medium instabilities, cumulative sum and exponentially weighted moving average control charts are used. This study proposes an assorted approach to monitor small, medium, and large disturbances in a single control charting procedure. For the evaluation of the proposed assorted control chart, we have used various measures like average run length, standard deviation run length, extra quadratic loss, relative average run length, and performance comparison index. A comparison of the proposed assorted control chart is presented with some typical charts including the Shewhart, cumulative sum, exponentially weighted moving average control charts, and some advanced modification such as combined Shewhart-EWMA (CSE), combined Shewhart-CUSUM (CSC), mixed EWMA-CUSUM (MEC), FIR EWMA, and adaptive EWMA (AEWMA). Finally, a real-life application example is presented to monitor the pH level of water in an ecotoxicology lab.