Performance of cumulative count of conforming chart of variable sampling intervals with estimated control limits

The control chart with cumulative count of conforming (CCC) items is very useful for high-quality processes. The current research of CCC chart performance with parameter estimation is focusing on the fixed sampling interval (FSI) scheme. In this paper, we investigate the effect of performance of CCC chart with variable sampling intervals with estimated control limits. The best design parameters of CCC chart with variable sampling intervals with known process nonconforming rate p0 are verified when such p0 is estimated with Bayesian estimator. The average time to signal (ATS) and its standard deviation (SDATS) are calculated when the high-quality process is in-control and out-of-control. Its efficiency is compared with that of FSI CCC chart, which shows a great cost reduction in practice.