Model-based requirements specification of real-time systems with UML, SysML and MARTE

Activities of specification, analysis and design of real-time systems (RTS) are highly dependent on an effective understanding of the application domain and on the thorough representation of their basic requirements. Model-based approaches using modeling languages such as UML are often applied to contribute to handle complexity of RTS development. However, UML alone does not completely represent important features associated with these systems, such as relationship with hardware elements and an effective representation of timing constraints. This article explores the combined use of UML and its profiles SysML and MARTE for modeling hardware and software requirements of RTS, with application to a case of controlling urban road traffic. The SysML profile alone does not present the representation of temporal, behavioral and performance requirements. The MARTE profile provides key resources to specify non-functional requirements for RTS, in addition to a clear description of the various relevant aspects of requirements definition of RTS, as for instance, temporal aspects and constraints. The main objective is to present the combined application of SysML with MARTE stereotypes, which enables the specification of different features of individual software requirements. Thus, in addition to the factors mentioned above, we can say that the proposed approach has an important role to specify RTS at different levels of detail and levels of abstraction.