This paper presents the experience the authors gained in applying formal methods - mainly MSC and SDL - when specifying a reactive system. The experience not onlydeals with the descriptions of the system, but also with the methodology used to develop the descriptions.
A large set of criteria to evaluate formal methods for reactive systems is presented. To make this set more comprehensible, it is structured according to a Concept-Model of formal methods. It is made clear that it is necessary to make the catalogue more specific before applying it. Some of the steps needed to do so are explained. As an example the catalogue is applied within the context of the application domain building automation systems to three different formal methods: SDL, statecharts, and a temporallogic.