Inventory model for deteriorating items with return and disposal

The paper considers an inventory model for deteriorating items in consideration for returns and disposals. At the end of each period the deteriorating items left unsold must be disposed of, but the new items left unsold can be returned to the supplier within limits and can also be disposed of without limit if necessary. The balance of new items is carried over to the next period as deteriorating items. The optimal inventory policies are obtained in two cases, that is, the demand for new items is independent of or dependent on one for deteriorating items.