Combining Scenario-based and Architecture-based Timing Requirements

The embedded systems used in the automotive domain belong to the most complex embedded systems. The automobile manufacturers permanently try to improve the safety and the comfort for the driver and the other passengers. Most of the developed embedded systems are time- and safety-critical. According to a study of Mercedes-Benz, 80% of the innovations in the automotive domain are driven by new electronic components and 90% of their functionality is realized in software. To cope with the increasing complexity in the design of automotive embedded systems, the automobile manufacturers use more and more the model-based software development instead of the classical programming. In requirements engineering, the first phase in the development process, the requirements on the system are elicited an d documented using natural language. Today, model-based approaches are only used to support the natural language. During the requirements engineering of an automotive embedded system, a requirements engineer has to specify and analyze the functional requirements on the system under development as well as the timing requirements. The functional requirements encompass especially the communication between the different parts of the system. Scenarios provide an intuitive way to model requirements on a reactive system and are therefore often used to specify the communication between the different parts of the system. In the scope of this thesis, we use a model-based approach to specify scenarios. Requirements on the timing behavior of the system are specified within the system architecture . In the automotive domain, many architecture description languages exist, for example EAST-ADL. Although the requirements engineer has to specify and analyze functional as well as timing requirements on the system, there does not exist a requirements engineering methodology that combines the two approaches. Therefore, we have developed a new requirements engineering methodology in the scope of this thesis. The methodology provides a systematic and holistic specification and analysis of functional and timing requirements on an automotive embedded system. Furthermore, we have developed two model transformations to support the requirements engineering methodology. The thesis closes with the evaluation of the methodology and the model transformations based on a body control module.