Neoteric ranked set sampling based combined Shewhart-CUSUM and Shewhart-EWMA control charts for monitoring the process location

Abstract

The use of efficient sampling designs can play a vital role to enhance the efficiency of the control charts for improved process monitoring. In this paper, the neoteric ranked set sampling scheme (NRSS) is used to design combined Shewhart-CUSUM (CSCUSUM) and Shewhart-EWMA (CSEWMA) control charts for monitoring of the process location with an aim to enhance the shift detection ability of these charts. Monte Carlo simulations are used to obtain the run lengths profiles of the proposed charts. The performance of the proposed charts is compared with their competing control charts using average run length, the standard deviation of run length, median run length and extra quadratic loss (EQL) as performance metrics. The proposed control charts emerged as more sensitive and in-control robust as compare to the existing charts. A real industrial dataset is used to demonstrate the implementation of the proposed charts for the practitioners. [Received: 11 May 2019; Accepted: 17 December 2019]