ABSTRACT
Since the rather deterministic days of hardwired relay logic, the proliferation of modern computing and communications technologies into the safety-critical railway signaling and control has posed a new challenge in the understanding and assurance of systems emergent properties, specifically safety. This transition has transformed the approach to design and implementation of control systems from electrical circuits to communicating and controlling functions implemented in software and firmware. A typical train control system is composed of many supervisory and control functions, and the concurrency, interdependency, and criticality pose a hugely complex dilemma to modern system designers in assuring overall system resilience and safety. In such a setting, it is necessary to systematically search and identify the undesirable system states at the earlier phases of the life cycle to save on effort and reengineering. A model-based approach to system representation, analysis, and safety/resilience assurance provides a proactive and potent tool in the face of pervasive complexity in modern train control systems.
