A Taxonomy of Modelling Decisions for Embedded Systems Verification

During model construction a number of decisions has to be taken. Often, decisions remain implicit, which has consequences for the correct interpretation of the model, and provides a source of miscommunication between different stakeholders and domain experts. We present a taxonomy of decisions guiding the modelling process and helping to distinguish, document and order the choices and assumptions involved. We focus on modelling of embedded systems, the purpose of the models we construct is formal verification. As a consequence we model both, control software and the controlled environment. Moreover, we aim at models in a formal representation, suitable for, e.g., model checking. The explicitness of modelling decisions allows to assess the quality of models and to clarify how meaningful verification results are. The taxonomy is a result of conceptual analysis and not bound to certain languages, methods, and tools. It can be used as complement for existing modelling methods.