In commerce, supply chain management (SCM), the management of the flow of goods and services, involves the movement and storage of raw materials, of work-in-process inventory, and of finished goods as well as end to end order fulfillment from point of origin to point of consumption. Interconnected, interrelated or interlinked networks.A supply chain is a system of facilities that procure of raw materials, transform them into intermediate fine goods and then final products, and finally deliver the products to customers through a distribution system that includes a (probably multi-echelon) inventory of system. Thus, it spans procurement, manufacturing, with effective inventory management as one key element. To fill orders efficiently, it is necessary to understand the linkages and interrelationships of all the key elements of the supply chain.