A model-based trace testing approach for validation of formal co-simulation models

Abstract

This paper presents a model-based trace testing (MBTT) approach to strengthen verification and validation techniques for formal co-simulation based wireless sensor network development (FoCoSim-WSN). This framework enables the functionality and protocol algorithms to be encoded in the controller model in the formal Event-B language. Use of proof tools can guarantee safety properties of this formal model. Also, network reliability and performance analysis is performed by MiXiM simulation including e.g. the network load distribution and the network latency. However, this framework lacks focus in validation coverage since test scenarios for the controller model are generated randomly from the simulation environment. Consequently, the MBTT technique is applied to validate the formal Event-B controller in co-models. This technique enables us to create test scenarios from the sequence of events in our co-simulation master algorithm. We use event trace diagrams, fault injection and recovery testing to specify functional, failing and recovery test scenarios. We define MiXiM co-simulation runs to generate long running test scenarios meeting our test requirements. The result shows how failing test scenarios in these runs (killer traces) enable model debugging in terms of absent or erroneous constraints and events.