This text analyzes the implication of modular architecture on buyer-supplier relationships. Considering modularity as a technological innovation, we study how product architecture and organizational architecture co-evolve. The text is structured with four chapters. First, we propose an analytical framework in order to study the impact of modularity on interfirm relationships. We stress the link between our work and dominant design paradigm and we underline the role of technology on organizational dynamic. Second, we present a synthesis on the debate between vanishing hand approach and Complex product system approach around the question of the frontier of the firm. Then we underline the specific case of automobile industry and we analyze what could be the impact of more modularity architecture on outsourcing decision. Third, we explain the close relationship between industrial architecture and product architecture. We show how the automobile firms (in particular suppliers) play an active role in order to build modular product architecture. But at the same time, we show that interstices (Penrose) continue to exist and SMEs can intervene at the top of the automobile supply chains. The last chapter studies the geographical dimension of modularity. We study on one hand how pure modular architecture contributes to increase the international fragmentation of supply chain, and on the other how imperfect modular architectures restrain the development of global value chains. We then do a focus on automobile supply chain. We propose to make a distinction between macro-component, meso-component and component. For each kind of parts, we study the centripetal forces and the centrifugal forces in order to build scenarios of location of suppliers' plants and centers of R&D. The conclusion is more prospective as we present some future research projects.
