Modeling Automatic Train Regulation Systems

Abstract

The increasing complexity of automatic train supervision and regulation systems (ATSIATR) has placed more and more inlportance on the use of modeling to describe and understand system behaviour. Such a model should provide a description suitable for requirement review and approval by the rail operator as well as detailed views for use by designers, implementers and testers. The Unified Modeling Language (UML) is a visual modeling standard that has been adopted by Alcatel to capture ATSJATR models. The choice of a standard notation was motivated by our need to exchange models with various stakeholders; the selection of UML in particular was influenced by its wide adoption in the software industry. We have gained our experience with using the Unified Modeling Language during the development of our latest generation product for train regulation and supervision. During this development we have defined an approach for requirements modeling and selected a useful subset of UML notations for analysis and design capture. UML has proven to be very effective at mapping from the requirements model to the analysis model to the design model and finally to implementation. We have found that this natural correspondence between models has simplified the task of reusing our code base on new projects and we believe it will be beneficial in the areas of maintenance and new feature incorporation.