An Improved S2 Control Chart for Cost and Efficiency Optimization

Virtually, detection of shifts in the dispersion parameter of the process is more valuable before monitoring the location parameter of the process. For the monitoring of the dispersion parameter, the S
²
chart is a common choice in the literature. In this paper, we proposed a modified S
²
chart based on modified successive sampling, which is cost effective relative to simple random sampling. The run length properties are used as comparative measure and the findings depict that all proposed schemes outperform the classical S
²
chart. Finally, the application of the proposed scheme is demonstrated using a real-life engineering process.