Managing a supply-chain involves controlling the flow of goods from the point of origin to the end-user. This definition is accurate whether the business is a manufacturing operation, fulfillment center, construction company, warehouse, or retail stockroom. In theory, all enterprises are supply-chain businesses, even businesses that provide services have assets that need to be managed according to supply-chain management principles. Heavyweights such as Walmart, Amazon, and Home Depot are extreme examples of supply chain management, using high amounts of company resources to manage the flow of merchandise through their stores and distribution centers. Smaller businesses may not need to allocate resources so intensely so long as they understand a few basic principles.