The economic order quantity (EOQ) model is a classical model used for controlling inventory and satisfying demand. Costs included in the model are holding cost per unit, ordering cost, and the cost of goods ordered. The assumptions for that model are that only a single item is considered, that the entire quantity ordered arrives at one time, that the demand for the item is constant over time, and that no shortages are allowed. Suppose we relax the first assumption and allow for multiple items that are independent except for a restriction on the amount of space available to store the products. The following model describes this situation: Let Dj = annual demand for itemj Cj = unit cost of itemj Sj = cost per order placed for item j 1 = inventory carrying charge as a percentage of the cost per unit Wj = space required for itemj W = the maximum amount of space available for all goods N = number of items The decision variables are Qi, the amount of item to order. The model is: Minimize lC;D; + 3* + 10, LC,Q,