We introduce a formal model of components as developed in the IST project OMEGA sponsored by the European Commission. The aim of this project is the definition of a development methodology in UML for embedded and real-time systems based on formal techniques.
The rationale of our component model is to provide additional structuring and abstraction mechanisms which allow a modeling discipline and the application of formal techniques based on ``interfaces''.
In the context of the OMEGA component model we also discuss the formal relationships between various levels of abstraction corresponding to UML concepts such as component diagrams, class diagrams, architecture diagrams, object diagrams, statecharts, and OCL. Finally, we discuss the possible usage of the OMEGA component model for compositional verification based on trace semantics.