Multi-Paradigm Discrete-Event Modelling and Co-simulation of Cyber-Physical Systems

In the modelling of Cyber-Physical Systems (CPSs), there are different possible routes that can be followed to gradually achieve a collection of constituent models that can be co-simulated with a high level of accuracy. This paper demonstrates a methodology which initially develops all constituent models at a high level of abstraction with discrete-event models expressed using VDM. Subsequently, a number of these are refined (without changing the interfaces) by more detailed models expressed using different formalisms, and using tools that are capable of exporting Functional Mock-up Units (FMUs) for co-simulation using the Functional Mock-up Interface (FMI). The development team of each of these more detailed models can then experiment with the interactions with all the other constituent models, using the high-level discrete-event versions until higher-fidelity alternatives are ready.