Interface definitions are important in complex system design, as they contribute to the definition and satisfaction of functional flows. Design Structure Matrix approaches have only recently focused on integrating possible interface types in conceptual design. In order to address the issue of interface definition, a physical interface data model is proposed in order to define the interface design space. Moreover, this data model is integrated into complex system architecture definitions in order to support collaborative conflict detection. The data in the physical interface data model is used as a basis for risk identification in the collaborative design space and associated shared design parameters.