In this paper we consider a Multi Person Multi Attribute decision problem in which a finite number of alternatives has to be scored on the basis of a finite number of criteria, using different Stakeholders' judgments. In particular, first we propose a new individual preferences aggregation method which takes possible Stakeholder's inconsistencies into account, measured by a new consistency measure we call μ-consistency, then we focus the attention on the aggregation process of the Stakeholders' preference structure about the criteria, preference structure which is represented by non additive measures defined over the space of the criteria.