On the roles of functions and objects in system specification

We present an analysis of the benefits and drawbacks of function and object based models in system specification. Functional models should be used for functional design space exploration and as a functional reference model throughout all design and validation activities. Object based models should be used for architectural design space exploration and as a design specification for the following design and implementation phases. Thus, the question is not which one to adopt in system specification, but how to integrate them. We argue that the integration should be based on an explicit formulation of design decisions with a tool handling the consequences of the decisions. In this way a functional model can be transformed into an object based model efficiently and systematically and a discontinuity in the design process is avoided. We consider it important that the question of benefits of functional and object based models is decided by means of experiments. To this end we propose an experiment that would confirm or falsify our hypothesis.