Side-sensitive synthetic double sampling X control charts

This paper develops two new synthetic double sampling (SDS) charts based on the revised side-sensitive (RSS) and modified side-sensitive (MSS) schemes for monitoring the location process parameter. In this paper, we first give the operation of the proposed charts and secondly, the exact form expression of the probability of declaring a sampling stage as 'conforming'. Thirdly, we investigate the zero-state and steady-state performances of the proposed charts in terms of the out-of-control average run-length, average sample size, average number of observations to signal and average extra quadratic loss. Finally, we compare the performance of the new charts with some well-known charts. It is observed that the proposed charts have attractive zero-state and steady-state properties and outperform the existing SDS chart and all other competing charts in many situations. An example of a real-life application is given to facilitate the design and implementation of the proposed charts. [Received: 28 February 2017; Revised: 14 March 2018; Revised: 28 August 2018; Accepted: 4 October 2018]