Verification Criteria for a Compositional Model for Reactive Systems

System compositioddecomposition has to be analyzed in terms of temporal constraints associated with the components' external interjiace. In this paper the analysis is focused on the propagation of temporal constraints along the structural hierarchy, thus showing that in many cases missing temporal constraints can be evaluated on the basis of the temporal constraints known. A set of criteria for the veriBcation of the temporal constraints in a compositional model is presented. A specific graphical notation is proposed. The application of the criteria to a real problem is illustrated by using TROL, an object-oriented real time language. Index term: Verijication, consistency, graphical representation, external specijication, requirements analysis, reactive system.