Title: A deterministic production inventory model with defective items, imperfect rework process and shortages backordered
Authors: Harun Öztürk
Addresses: Department of Business Administration, Faculty of Economics and Administrative Sciences, Süleyman Demirel University, 32260 Çünür, Isparta, Turkey
Abstract: The basic assumption of the conventional inventory models is that all items produced are of perfect quality. In practice, some defective items are produced due to process deterioration or other factors. This paper develops a mathematical model for an imperfect production inventory system. It is assumed that the defective items produced in the regular production process consist of scrap, imperfect quality and reworkable items. The rework process is accomplished immediately when the regular production process ends, and the rework process produces scrap, imperfect quality and as-good-as perfect items. A numerical example is provided to illustrate the developed model, and a sensitivity analysis is carried out. It was found that producing scrap and imperfect quality items through the reworking is crucial, since this assumption effects optimal policy. Managerial insights are also presented based on the numerical examples.
Keywords: inventory management; production planning; screening; defective items; imperfect rework process; shortages.
International Journal of Operational Research, 2020 Vol.39 No.2, pp.237 - 261
Received: 16 May 2017
Accepted: 28 Jan 2018
Published online: 07 May 2020 *