An EOQ inventory model with partial backordering and reparation of imperfect products

In many situations of real life, the products are manufactured from a supplier that is located very far from buyer. Moreover, the lot contains some products which have imperfect quality and the defective products cannot be replaced with perfect ones immediately. In order to identify imperfect products, the buyer conducts a screening process. The imperfect products are fully valuable and repairable therefore they are withdrawn as a single lot from inventory and sent to a local repair shop. After reparation process, the repaired products are returned to the buyer store. Considering the time when the lot of repaired products arrives to the buyer store, four cases are identified and studied. The optimal solution to each case is derived. The applicability of the proposed inventory model is illustrated with a numerical example.