This document discusses options for multi-echelon forecasting and replenishment between stores and warehouses. It describes three main options: Single Point Replenishment (SPR), Distribution Requirements Planning (DRP), and Multiple Point Replenishment (MPR). SPR uses a historical method but is not optimized for multi-echelon. DRP forecasts store orders and rolls them up, but store forecasts can be inaccurate. MPR uses store point-of-sale data offset by lead times, allowing promotions to accurately impact warehouse forecasts, but does not respond to changing store inventory levels. The document also notes that forecast accuracy increases with product groups rather than individual items.