Economic production quantity model considering warm-up period in a cleaner production environment

Currently, the primary objective of every manufacturing organization is in customers' satisfaction and system cost reduction while keeping in mind both production quantity (economic issues) and environmental issues (sustainability). This study investigates the effects of machine warm-up period on an imperfect production process with rework. In this case, the maintenance process is intended to maximize the efficiency and effectiveness of the production machine. In this manufacturing system, it assumed that after the setup time, the machine starts at the lower rate than the regular production process, commonly called as warm-up period. The warm-up period will increase the useful life of the machine. On the other hand, the machine's defects that occur during this warm-up period are identified and repaired before the regular production starts. Also, this warm-up period reduces waste as it improves machine performance; resulting in the decrease of scrapped items that makes the process friendly for the environment. The purpose of this proposed model is to determine the optimum value of production quantity to minimize the total costs by considering the warm-up period and set-up time. Finally, numerical experiments have been conducted to validate the efficacy of the model as well as to obtain some managerial insights.