“…In a bid to further increase the sensitivity of the control charts to small, moderate and large shifts, several design strategies and modifications of the control charts have been introduced by researchers, which have led to the development of new control charts. For some relevant papers on these new control charts, readers are referred to Capizzi and Masaroto, 4 Al‐Shabah, 5 Abbas et al 6 Graham et al 7 Abujiya et al 8 Abbas et al 9 Lu, 10 Sanusi et al 11 Aldosari et al 12 Haq, 13 Haq et al 14 Nawaz et al 15 and Adeoti and Malela‐Majika 16 . All of these control charts, as in the case of many papers, are based on the assumption that process parameters are known.…”