From Object Speciication towards Agent Design ? No. 8319 Modelage (a Common Formal Model of Cooperating Intelligent Agents)

Nowadays, object speciication technology is successfully used for modelling information systems. However, object-oriented modelling cannot cover all aspects (e.g. dynamic behaviour evolution) of such systems. A promising approach to get a grasp of these additional requirements for modelling information systems is the speciication of systems as communicating, cooperating and autonomous agents. In the present paper we sketch an evolutionary extension of object speciication towards agent modelling. Here, we have to emphasize that this paper is not intended to ooer perfect solutions. Our aim is to discuss and x a research agenda for a formal agent approach which promises to provide a semantically richer framework for the speciication of information systems. 1 Motivation Object-oriented modelling of information systems has become a widely accepted approach. Object-oriented data models allow to describe the structure of application domains in an adequate way. In addition, several approaches make it possible to specify the dynamic behaviour of objects and object systems. In general , versions of temporal and dynamic logic are used for this purpose. However, it seems that the concept of \object" (at least in its current understanding) cannot cover all aspects of information systems. A new concept, the concept of agent which can be seen as a further development of \object" is currently emerging as an important concept in many elds of Information Technology. The key facets of the concept agent appear to be goal, state, behaviour, and heterogeneity. Considering the modelling of heterogeneous information systems (e.g. Buc90, Bro92]) motivates the identiication of \objects", each of them incorporating some knowledge about an application domain (like facts, rules, strategies, etc.) and being a unit of design that can be composed with other objects via aggre-gation and specialization hierarchies (cf. HJS92, SJH93]). Whereas structural aspects of such systems can easily be dealt with by current object-oriented approaches , these approaches succeed to cope with dynamic behaviour only up to a certain degree.