Gauge imprecision and multivariate process capability analysis

Alternative definitions of Multivariate Process Capability Indices (MPCIs), based on different approaches, have been proposed in literature. The research works related to MCPIs assume no gauge measurement errors. However, in industrial applications, despite the use of highly advanced measuring instruments, account needs to be taken of gauge imprecision. In this paper we study the effects of measurement errors on multivariate capability indices computed using the principal components analysis. The results show that measurement errors can alter the results of a multivariate process capability analysis.