The Synchronous Paradigm proposes an abstract model integrating concurrency and communication, deterministic thus simple, semantically well-founded thus suitable to formal analysis, producing safe and efficient code. However combining this model with the object-oriented approach is still challenging. This paper explores how an UMLbased methodology can be set up, making it possible to use the Synchronous Paradigm in combination with other (more classical) techniques to develop control-dominated systems. It addresses the issue of representing behavior in a semantically sound way using the synchronous models, of relating behavior and structure, and of mixing synchronous and asynchronous behavior though an extended notion of (ROOM-like) “capsules”, the synchronous islets. We also briefly mention the extensions and modifications in the UML meta-model necessary to support this methodology.