Economic production quantity with imperfect production processes and learning effects

The fundamental assumptions of the classical economic production quantity (EPQ) model are that the production rate is constant and 100% of items in each production lot are perfect. These assumptions are not always pertinent while learning is in progress, production process deterioration, or other factors happen. Therefore, this study investigates the effects of learning and imperfect quality items on the EPQ model. The system is assumed to deteriorate during the production process and produce some proportion of defective items. A mathematical model is derived to determine the optimal production quantity. Numerical example and sensitivity analysis are presented to illustrate important issues related to the developed model.