The Metro Rio ATP case study

This paper reports on the Simulink/Stateflow based development of the on-board equipment of the Metro Rio Automatic Train Protection system. Particular focus is given to the strategies followed to address formal weaknesses and certification issues of the adopted toolsuite. On the development side, constraints on the Simulink/Stateflow semantics have been introduced and design practices have been adopted to gradually achieve a formal model of the system. On the verification side, a two-phase approach based on model based testing and abstract interpretation has been followed to enforce functional correctness and runtime error freedom. Quantitative results are presented to assess the overall strategy: the effort required by the design activities is balanced by the effectiveness of the verification tasks enabled by model based development and automatic code generation.