Nonparametric control charts based on Mahalanobis depth

Abstract

This study concerns the use of r and Q control charts based on data depth to control process involving multivariate quality measurements. In this paper, firstly the concept of data depth is introduced in order to construct quality control chart structures, the characteristics of data depth are given and statistics based on this concept are obtained. Following this, the structures and interpretations of mainly nonparametric r and Q control charts are explained for the Mahalanobis depth measure used in statistical quality control by means of an example.