Abstract
In this paper a formal model for asynchronous systems behaviour is presented which is suited for representing all levels of abstraction appearing in the design process. Based on a structural abstraction of asynchronous computation systems called asynchronous nets the behaviour of an asynchronous system can be represented by a set of so called abstract computations. It is shown how basic properties of such systems, and in particular, delay-insensitive behaviour, could be determined by investigating properties of abstract computations. Finally, it is demonstrated that the model enables formal verification of asynchronous systems over different levels of abstraction.