State transition modelling applied to tunnel ventilation control

IST Ltd has applied modern state-based behavioural modelling techniques to the development of specifications for major transportation applications. In particular, these techniques have been applied to the definition and analysis of tunnel ventilation control requirements for CrossRail. The technique has permitted the early prototyping of some of the algorithms required, resulting in the production of a clearer and more accurate specification that better takes into account the complexities of different operating modes and operational scenarios. The model potentially can be elaborated throughout future phases of system design to result in an implementation that is traceable back to the requirements specification. The production of a safety case is facilitated by this approach.