Abstract: Based on the traditional model of quantity discount, it is amended for the case of gross amount discount to make the model more practical. Specific solution procedure and algorithm are proposed to solve the amended model. Also, numerical examples as well as sensitive analysis are presented. The result shows that when the supplier offers gross amount discount, partial ordering policy does not always dominate full ordering policy, but changes with parameters. The model is more practical and easier to apply in the production and sale of joint multi-item replenishment.

Key words: multi-item, jointly replenishment, gross amount discount, economic order quantity (EOQ)