Modeling the railway control domain rigorously with a UML 2.0 profile

We introduce the Railway Control Systems Domain (RCSD) profile of the Unified Modeling Language UML 2.0 as a domain specific modeling language for railway and tramway control systems. The RCSD profile covers the segments of the rail network, sensors, and control elements like signals and switches. Using these terms of the railway domain, it facilitates the communication between domain experts and specialists for embedded control system development. Defined as a profile for UML 2.0, the development of precise RCSD descriptions is supported by standard UML tools, visualizing railway networks in the same way as domain experts are used to. The static description of networks is complemented by the characterization of the dynamics within the network with trains running on predefined routes. This behaviour is provided by the semantics of a state transition system derived from the object diagram of a particular network model. This rigorous semantic approach constitutes a prerequisite for further tool-supported analysis of safety requirements, and generation of the actual control system.