Abstract

This paper proposes a new approach based on a synthetic control chart to monitor the simple linear profiles in Phase II. The proposed chart is based on the simultaneous use of three independent synthetic control charts developed to monitor intercept, slope, and error variance parameters of the simple linear regression model. The individual synthetic control charts of the proposed synthetic chart are developed by using three Shewhart-type control charts presented by Gupta et al. (2006) to monitor parameters of simple linear profile regression. The proposed chart is referred to as the Synthetic Shewhart-3 chart. The average run length criterion is used to assess the effectiveness of the Synthetic Shewhart-3 chart proposed in detecting sustained shifts in the intercept, slope, and error variance. A detailed comparison is conducted between the Synthetic-Shewhart-3 chart and other charts for monitoring simple linear profiles to determine their performance. Simulation results revealed the good performance of the proposed Synthetic Shewhart-3 chart. Finally, the implementation of the proposed chart is illustrated through an example.