System for replenishing merchandise based on actual consumer demand. Prior methods of inventory replenishment were order driven, relying on retailers and wholesalers to predict demand. ECR is demand driven, initiating the manufacture and shipment of goods based on consumer purchase activity. ECR reduces the cycle time from purchase to replenishment, reduces the cost of warehousing excess inventory, and assists retailers, wholesalers, and manufacturers in determining the optimum product mix. ECR predicts the impact of a product promotion on retail demand and production requirements. ECR is dependent upon the efficient and timely sharing of data along the supply chain beginning with sales information collected at a point-of-sale terminal. Given thin margins on average transactions and significant expenditures on warehouse space, some food and drug retailers resist manufacturers’ ECR initiatives.