Abstract: This article presents a system designed to help deciders manage cases of crisis. The system represents, characterises and interprets the dynamic evolution of a given situation and displays the results of its analysis. The core of the system is made of three multiagent systems (MAS): the data representation MAS for the static and dynamic representation of the current situation, the characterisation MAS for dynamically regrouping sets of agents of the data representation MAS and the interpretation MAS for matching results between the characterisation MAS and previous scenarios stored in the persistent memory of the system in order to have a deeper analysis of the situation. The case based reasoning of the interpretation MAS sends its results to the user as a view of the current situation linked to some views of similar situations. This article will focus on the data representation MAS.