Resumen
The field of speech act based modelling of information systems has attracted an increasing attention in recent years. On the basis of the research work of Winograd and Flores, several modelling approaches have been proposed. In this paper we discuss the speech act based modelling approaches in general and the DEMO approach in particular. Next to the discussion of theoretical foundations of this modelling approach we also illustrate the application of DEMO to a case study, and we report on the status of the resulting models for information systems design and business process optimisation.