Formal modelling and analysis of computerized control in rail transport: a case study

The formal modelling and analysis of computerized real-time control systems is emerging as a new and important topic of research in both the control systems and software engineering literature. Formal modelling helps makes precise the specifications of what must be done which in turn makes possible the formal analysis required to establish guarantees about certain aspects of system behavior. This is especially true when there is a possibility of risk to human life. The authors describe some modelling and analysis work performed with a Petri net oriented CASE tool, Design/CPN from MetaSoftware, to model and analyse the behavior of a real-time control system to open and close the doors of a prototype subway train, in response to pushbutton commands from the (human) operator.