“…It has an effective charting structure that exhibits robustness for the skewed distributions. Alemi and several other authors have studied its properties such as Khaliq et al , Lee et al , Torng and Lee, Lee and Torng, Tercero‐Gomez et al , and Torng et al , among many others. The control limits for this chart are defined a where Q 1 and Q 3 are the first and third quartiles, Q 2 is the median, IQR is deviation of Q 1 and Q 3 , i.e., inter‐quartile range (IQR) is defined by Q 3 −Q 1 , and L is the control limits coefficient that may be fixed at a pre‐specified value of average run length (ARL), denoted by ARL 0 for an in‐control process.…”