The growing importance of exchanges and collaborations in all business areas calls for fast, efficient, and flexible models of computersupported cooperation. As the traditionnal client-server paradigm is hampered by its structural limitations, the interest of the Information System Community is aroused by the promises of alternatives known as peerto- peer approaches. This paper introduces a generic architecture, P2P Coop, designed for the execution of collaborative business processes. Basic motivations of the model are discussed, as well as major contributions notably in terms of service-oriented routing and failure handling.