Abstract In a production process, when quality of the product depends on more than one characteristic, ‘Multivariate Quality Control’ ( MQC ) techniques are used. Many MQC techniques have been developed to control multivariate variable processes, but not much work has been reported on...

Abstract Wu and Spedding [Journal of Quality Technology 32: 32-38, 2000] have proposed the synthetic control chart to detect small shifts in process mean. In this paper, for the same problem, we propose a control chart called ’Group Runs’ (GR) control chart, which is a combination of...

Measurement error is a usually met distortion factor in real-world applications that influences the outcome of a process. In this paper, we examine the effect of measurement error on the ability of the EWMA control chart to detect out-of-control situations. The model used is the one involving...