Combined Variable Sample Size, Sampling Interval, and Double Sampling (CVSSIDS) Adaptive Control Charts

Abstract

In this article, an adaptive chart which combines variable sample sizes, sampling intervals, and double sampling features called CVSSIDS control chart is proposed, which uses three different sample sizes, two different sampling intervals, two warning limits, and two different control limits. To evaluate the efficiency of the proposed scheme versus different schemes, average time to signal, average number of samples to signal and average number of observations to signal are utilized. In addition, the minimum ATS values of the proposed chart are computed. Finally, the proposed chart is compared to standard Shewhart (SS) chart and several adaptive control charts.

Keywords:

• Adaptive control charts
• Double sampling
• Average time to signal
• Average number of samples to signal
• Average number of observations to signal; Markov chain