A Comparison of Average Time Rate with range and variance chart when using variable sampling interval

변량표본추출간격을 이용한 범위관리도와 분산관리도의 ATS비교

The basic of the VSI charts is that if the sample statistic computed after a sample is taken shows some indication of a process change than the sampling interval before the next sample should be short otherwise long. This paper was shown the VSS chart can be considerably more efficient than the FSS chart and the effectiveness of VSI R chart with S chart used for monitoring a process standard deviation.