Abstract: Methods and systems for managing supply chains are disclosed. Replenishment of items within retail stores and distribution centers is optimized to respond to real-time demands. One method includes determining optimized inventory positions based on demand probability distributions. Items are stocked at locations within a supply chain in order to support efficient movement of items to customers. Inventory levels are maintains in real time. Proactive and reactive demand signals are received and are processed to trigger movements of items within the supply chain to fill orders and replenish stocks in anticipation of future customer demand.