Résumé
This paper presents an extension of the AGR (Agent-Group-Role) organizational model, called AGRE (AGR + Environment), which includes physical (or simply geometrical) environments. This extension is based on the concept of a space which can be seen either as a physical area or as a social group, and on a clear distinction between an agent and its mode, i.e. the way it appears and interacts into a space with other agents. A notation which encompasses both social and physical environments is given.