Traditionally, supply chain management practices have been static: Firms, like Dell, tend to rely on long-term relationships with key trading partners, like Microsoft. Market efficiency would surely increase if more dynamic supply chains were in place instead, giving firms easy access to information about changing market conditions and allowing them to alter their trading partners accordingly. Despite the potential benefits of such flexibility, the inherent complexity of managerial decisions in dynamic supply chain settings has thus far inhibited their widespread adoption. The Trading Agent Competition in Supply Chain Management (TAC SCM) is a model of dynamic supply chain management that is intended to stimulate research on technologies that could make dynamic supply chain management feasible.