Published on October 29, 2007
Unifying MAS Meta-Models ADELFE, Gaia & PASSI: Unifying MAS Meta-Models ADELFE, Gaia & PASSI Carole Bernon, Massimo Cossentino, Marie-Pierre Gleizes, Paola Turci and Franco Zambonelli Agent-Oriented vs. Object-Oriented: Agent-Oriented vs. Object-Oriented Design a system Instantiate a meta-model OO context - design rely on a common denominator Universally accepted concept of object and related meta‑model of object-oriented systems AO context - to date, no common denominator Each methodology has its own concepts and system structure In the agent world the meta-model is the critical element when applying the “method engineering” paradigm Reasons to Unify: Reasons to Unify Meta-model = means to unify concepts Unique meta-model, a way of unifying the different concepts Helping designer to build a meta-model depending on the system he needs Choice of useful elements From the “omni-comprehensive” MAS meta-model Composition of process “Method fragment” selection phase Model coherence checking by CASE tools Unification eases model transformation MAS Meta-Model for ADELFE: MAS Meta-Model for ADELFE no predefined organization local goal cooperative detect and remove NCS Gaia Methodology: Gaia Methodology First version Designed to handle small-scale, closed agent-based systems Modelled agents, roles, interactions Missed in modelling explicitly the social aspects of a MAS Official extension of Gaia Thought for open agent systems Focused on the social organization of the system MAS Meta-Model for Gaia: MAS Meta-Model for Gaia MAS Meta-Model for PASSI: MAS Meta-Model for PASSI Towards a Unifying MAS Meta-Model: Towards a Unifying MAS Meta-Model In order to define a unifying meta-model we will consider the following specific aspects: Agent structure Agent interactions Agent society and organizational structure Agent implementation Agent Structure: Agent Structure ADELFE: cooperative agents Gaia and PASSI: composition of roles Agent Structure - Considerations: Agent Structure - Considerations None imposes a specific classical agent architecture Seen as some kind of low level architectures that can be adopted during MAS implementation None explicitly deals with goals and plans ADELFE Notion of goal is only used to determine skills Plans are built at run-time by the system Gaia The concept of “goal” is implicit in roles Plans play no explicit role PASSI Goals are considered as non functional requirements Plans are modelled as algorithms (activity diagrams) Agent Interactions: Agent Interactions No relevant differences Agent Interactions: Agent Interactions No relevant differences ADELFE: agents can communicate indirectly using environment Gaia: communication mediated by the environment seen as a side effect Agent Interactions: Agent Interactions No relevant differences ADELFE: ontologies have not to be modelled; agents are able to adapt to the environment and other agents ADELFE: agents can communicate indirectly using environment Gaia: communication mediated by the environment seen as a side effect Agent Society and Organizational Structure: Agent Society and Organizational Structure ADELFE: no predefined organization Agent Society and Organizational Structure: Agent Society and Organizational Structure ADELFE: no predefined organization Gaia: organization = primary abstraction PASSI: services and scenarios Agent Implementation: Agent Implementation ADELFE The problem of the system implementation has not been treated yet; no platform has been imposed Gaia Totally abstract from implementation PASSI FIPA compliant systems Direct map among the most important elements of the model and their implementation Proposal for a Unifying Meta-model: Proposal for a Unifying Meta-model Conclusion: Conclusion Societies with or without predefined organizations (open systems) Generic agent (cooperative or not) Follows organizational or cooperation rules Possibility of identifying three domains Improvements: an agent has a representation of the environment expressed via an ontological model Step towards a unique meta-model A unifying framework for the systems produced with different approaches Open Questions: Open Questions Can a unique meta-model exist? What description level has to be reached? How may designers choose meta-model elements? What kind of tools may ease their work?