Modelling Undefined Behaviour in Scenario Synthesis

Current approaches to scenario synthesis do not distinguish, in the resulting state machine models, proscribed behaviour from behaviour that has not yet been defined. In this paper we propose using partial labelled transition systems (PLTS) to capture what remains undefined of the system behaviour. In the context of scenario synthesis, we show that PLTSs can be used to provide feedback to stakeholders on the parts of the behaviour specification that need further elaboration. In this way we aim to support the iterative incremental elaboration of behaviour models.