Economic production quantity model for items with imperfect quality subject to learning effects

Salameh and Jaber [2000. International Journal of Production Economics 64, 59-64] developed an inventory situation where items received are not of perfect quality (defective), and after 100% screening, imperfect quality items are withdrawn from inventory and sold at a discounted price. This paper extends the work of Salameh and Jaber by assuming the percentage defective per lot reduces according to a learning curve, which was empirically validated by data from the automotive industry. Mathematical models are developed with numerical examples provided and discussed. The developed model was compared with the model of Salameh and Jaber to emphasize the importance of learning.