Inventory is used to satisfy current and future needs and accounts for 50% of capital in some organizations. Maintaining the right inventory levels is important to avoid excessive costs from too much inventory and stockouts from too little inventory. There are several reasons to hold inventory, including decoupling supply and demand, storing resources, handling irregular supply and demand, taking advantage of quantity discounts, and avoiding stockouts. Determining how much and when to order are important inventory control decisions, which can be addressed using economic order quantity models and reorder points. Quantity discounts provide reduced unit prices for large orders.