ion from the implementation they use. Some tools rather consequently use this abstract model; others at least partly keep the implementational view, modeling components, e.g., by object communicating by method call. Furthermore, tools generally support only either event-driven or time-driven models, focusing either on the reactive or the control part of an embedded system without integrating those application domains. Besides the underlying model, they also differ concerning the offered process support, especially concerning the consistency mechanism. Generally, all tools support syntactic consistency (e.g, well-formedness of trigger conditions). Tools do generally not support semantic consistency with few exceptions exist (e.g., a non-determinism check, checking whether a sequence diagram can be executed by state machines).1 Model-based Development: Picture of the Future To increasing both the efficiency of the development process, and the quality of the development product, model-bas...