The PROMETHEE-GAIA decision support system for multicriteria investigations

In this paper the interest to treat economical problems by multicriteria tools is first discussed. An example is proposed. The PROMETHEE-GAIA multicriteria methodology is then briefly recalled. PROMETHEE is the normative approach, GAIA is the associated visual interactive modelling module. A space of freedom for the decision-maker in the GAIA plane is considered by allowing some variations on the weights giving the degree of relative importance of criteria. PROMETHEE VI allows to detect if the multicriteria problem is hard (difficult) or soft (easy). PROMETHEE V is also described, additional constraints can then be taken into account. The methodology is illustrated by the application of the associated PROMCALC software on the example.