A Combinned Control Chart to Monitor Small Process Mean

This article proposes a new control chart, which has better performance in detecting small shifts. It combines npx and CRL control chart, and the ring gage is used to classified conforming and nonconforming items. The combined chart employs attribute inspection which is easier to operate in monitoring. At the same time, the combined chart makes up for the shortcomings of the lack of accuracy of the attribute chart, it performs well when the mean shift is small.