Inventory Management involves determining optimal ordering and stocking policies to balance holding costs, ordering costs, and stockout costs. Classic models include: (1) Economic Order Quantity (EOQ) - determines optimal order size Q* = √(2DS/H) where D is demand rate, S is ordering cost, H is holding cost; (2) Economic Production Quantity (EPQ) - extends EOQ for production scenarios; (3) Newsvendor Model - single-period stochastic demand; (4) (Q,r) policy - order Q units when inventory drops to reorder point r; (5) (s,S) policy - order up to S when inventory falls below s. Advanced topics: multi-echelon inventory, stochastic inventory models, and inventory optimization under uncertainty.