A major role in business operations is the way in which supplies are managed. Supplies should be as small as possible, but always enough to meet the needs of customers, consumers and users. Poor quantities of inventories bring many problems and adverse effects on production, trade and distribution. On the other hand, too much supplies of inventories causes unreasonably high costs of stockholding. Models for determining the optimal supplies quantity are: ABC analysis, XYZ analysis, and Cross ABC and XYZ analysis. Inventory management models are divided into traditional and contemporary models. Traditional models include EOQ, economical order quantity model, continuous monitoring system and periodic monitoring system. In today's inventory management models we include: the Material Requirements Planning System (MRP I), the Resource Need Planning System (MRP II), the Distribution Resource Planning Model (DRP), Enterprise Resource Planning (ERP), and Just in Time (JIT) System. Traditional models are the oldest and simplest inventory management models, and are complemented by modern inventory management models. With the development of information technology, the impact of precision forecasting of demand behavior and market changes is more efficient.