Process-targeting model for a product with two dependent quality characteristics using acceptance sampling plans

Abstract

The purpose of this paper is to develop a process-targeting model for a product with two quality characteristics produced by two processes in series. The first quality characteristic is determined by the setting of the first process, whereas the second quality characteristic depends on the setting of the two processes. The quality of the product is controlled by a single sample inspection plan where inspection is assumed to be error free. The objective of the model is to determine the optimal target for both processes that maximises the profit. A realistic case study is used to demonstrate the utilisation of the model. The results of applying the model indicated that the plant could improve its profit by using optimal process setting and better inspection plans parameters. In addition, sensitivity analysis was performed to study the effect of different parameters on the expected profit and optimal processes means.

Keywords:

• quality control
• process targeting
• quality characteristics
• sampling plans

Acknowledgements

The authors wish to acknowledge the support provided by the Department of Systems Engineering and the excellent facilities provided by King Fahd University of Petroleum and Minerals (KFUPM), Dhahran Saudi Arabia for conducting this research. They also thank Professor M. A. Rahim for his valuable comments which have improved the presentation of the paper.