Model Engineering using Multimodeling

Abstract

Abstract. We study the simultaneous use of multiple modeling tech-niques in the design of embedded systems. We begin with a pre-existing Statecharts model of a simple case study, a traffic light for a pedestrian crossing, using it to illustrate the need for multimodeling and the pit-falls. The original model combines two distinct models of computation (MoCs), finite state machines (FSMs) and synchronous/reactive (SR). We add an additional MoC, a discrete-event (DE) model of the environ-ment in which the traffic light operates, including a simple fault model, yielding a model that combines three different modeling techniques. We construct a second model of a hardware deployment and a third model that is an abstraction used for formal verification. The result is that this simple example uses three distinct models of the system (functional, deployment, verification), two of which hierarchically combine distinct modeling techniques (DE, SR, FSM). This exercise reveals some pitfalls of model-based design where multiple models are needed as well as some of the opportunities. 1