On efficient estimation strategies in monitoring of linear profiles

Abstract

A fundamental strategy to diminish variations in manufacturing process urged the practitioners to characterize the quality of a process by a relationship between the response variable and one or more explanatory variables instead of a single quality characteristic; this state is known as a profile or a function. Profile monitoring mainly aims to test the stability of this relationship. Many researches have been carried out to study the different sampling techniques in the performance of linear profile under the maximum likely hood (MLE) estimation strategy, whereas using different estimation strategy has not been discussed so far. This paper is dedicated to introduce Bayesian estimation strategies with a proposal of novel control charts for jointly monitoring the linear profile. We considered restricted and pretest estimators, besides the estimation of distrust probability under the null hypothesis. Analytical and numerical results showed that the proposed estimators outperformed the MLE method. The proposed control charts have been used to monitor the two-phase flow in the oil industry to control the relationship between the flow rate and the pressure difference between two points. - 2018, Springer-Verlag London Ltd., part of Springer Nature.