Composite systems generally comprise heterogeneous components whose specifications are developed by many development participants. The requirements of such systems are invariably elicited from multiple perspectives which will overlap, complement and contradict each other. If these requirements are developed and specified using multiple methods and notations respectively, then it is necessary to express and check the relationships between the resultant specification fragments. In this paper we deploy multiple “ViewPoints” that hold partial requirements specifications, described and developed using different representation schemes and development strategies. We discuss the notion of interViewPoint communication in the context of this ViewPoints framework, and propose a general model for such communication. We elaborate on some of the requirements for expressing and enacting inter-ViewPoint relationships, and use fragments of the requirements specification method CORE to illustrate o...