According to the Gale Encyclopedia of E-Commerce, edited by Laurie J. Fundakian and available here:
Supply chain management is the practice of using the Web and other information technologies to coordinate and keep track of supplies as they move through a business's supply networks. The simultaneous goals of supply chain management are to quickly meet customer demand—by, for instance, fulfilling their orders in a timely fashion and offering them accurate projections—and to minimize costs by reducing inventories and making supply chains optimally efficient. In an age of increased outsourcing and larger webs of business relationships in the global economy, supply chains have become particularly complex, making them increasingly difficult for individual firms to control. The proliferation of electronic business relationships, in the forms of extranets and online business-to-business exchanges, made supply chain management both tempting and technically feasible. Supply chain management was thus a quickly emerging, if still problematic, element of business-to-business e-commerce into the twenty-first century.