A new control chart to monitor the mean vector of a trivariate process

Abstract

AbstractFor trivariate normal processes, ‘Trivariate Weighted Alternated Charting Statistic’ (Tri‐WACS) control chart is proposed to monitor a mean vector. In ACS chart, two/three quality characteristics (X, Y)/(X, Y, Z) are monitored alternately. The proposed Tri‐WACS chart is based on the weights of each of the quality characteristics. These weights are used to decide how many samples are to be inspected successively corresponding to the respective quality characteristic, and to make a decision whether the production process is under statistical control or not. It is numerically illustrated that Tri‐WACS chart is more efficient as compared to the related control charts.