ABSTRACT
Manufacturers have increasingly emphasised improving process performance and equipment effectiveness in their routine operations. Therefore, this paper integrates maintenance, production, reliability and free-repair warranty (FRW) programs into an economic production quantity model of an imperfect process with an increasing hazard rate. Such a production system should be periodically inspected and maintained to retain a reliability value higher than a prespecified value r. The system is replaced following an out-of-control production run period or when the reliability falls below r. If the production run period is in the out-of-control state, then the defective items are reworked. In this paper, an inferior item is defined as an item that satisfies specifications during inspection but is likely to incur postsale servicing costs when sold under FRW. Reworked items are assumed to incur a higher postsale servicing cost than do defect-free items. The optimal N and lot size that minimise the total cost are discussed herein. Finally, a numerical example is presented to illustrate the model.
Acknowledgment
The author is pleased to thank the three anonymous referees and the editors for their valuable comments and suggestions, which significantly improved the clarity of this paper.
Disclosure statement
No potential conflict of interest was reported by the author.
Additional information
Funding
Notes on contributors
Gwo-Liang Liao
Gwo-Liang Liao is an associate professor of Information Science and Management Systems at the National Taitung University. He received his M.S. (1992) and Ph.D. (2005) degrees in Industrial Management from the National Taiwan University of Science and Technology. His current research interests include reliability engineering, warranty policies and production management. He has published in journals such as IEEE Transaction on Reliability, Reliability Engineering & System Safety, International Journal of Advanced Manufacturing Technology, European Journal of Operational Research, International Journal of Reliability, Quality and Safety Engineering, International Journal of Systems Science, Journal of Intelligent Manufacturing, Applied Mathematical Modelling, IEEE Transactions on Systems Man and Cybernetics: Systems, International Journal of Production Research and International Journal of Production Economics.