The spatial decision support frequently relies on multicriteria analysis methods. An innovative approach is to combine the spatial aspects through the use of GIS and MAS tools.We try, through this research task, to show the interest of such an association for the study and the decision aid of space-time processes. Our contribution relates to the elaboration of a spatial decision making process adapted to the needs of the professional users designed by an assembly of two independent models. The objective of the first component is to represent the decision strategies considering the interactions between the criteria and resting on an interactive step in multicriteria evaluation. The second component ensures the negotiation and the participation of a great actor's diversity.