This chapter intends on explicitly building the model to create a language for supply chain economics. It defines a system for a new project-oriented industrial organization economic model for procurement in the construction supply chain. The chapter develops the model through the synthesis of the principles within the industrial organization literature and the supply chain literature. It proposes a new model to describe the structural and behavioural characteristics of procurement along the construction supply chain using a hybrid project-oriented industrial organization economic approach and does so by assembling the components of the model from first principles. The model assists in developing a framework to describe industrial organization of project-based industries supply chains and, in particular, the construction supply chain. The firm supplies a product, a service or a product and a service within a transaction. Firms may supply more than one commodity type and, therefore, firms may be competing in a number of markets.