09h00 - 10h00
PROMETHEE: The Past - The Present – The Future
Some views on the mathematical modelling approaches having been proposed for management and decision will first be considered, especially with regard to single and multiple criteria optimisation. For multicriteria decision making (MCDM) problems only compromise solutions can be considered. Decision-makers have to provide additional information reflecting their preferences. Their brain is involved. The initial PROMETHEE methodology will then be explained. The additional information consists in a parameterisation of the decision problem: a preference function has to be associated to each criterion and weights measuring the relative importance of all of the criteria have to be defined. A fair distribution of these weights should be achieved: this is an ethical problem. This parameterisation is particularly easy to understand for decision makers, which is an important advantage of PROMETHEE. It makes it possible to eliminate all scale problems for the criteria. Pairwise preference indices are then computed by comparing each pair of alternatives. Outranking and outranked flows as well as multicriteria profiles are finally calculated for each alternative. Based on these computations PROMETHEE I provides a partial preorder on the set of the alternatives and PROMETHEE II a complete one. The GAIA visual interactive model that was developed later in collaboration with Bertrand Mareschal will also be presented. It provides decision-makers with a graphical representation of all the alternatives and all the criteria. A decision-stick and a decision-axis, as well as the brain of the decision-maker itself can also be displayed on the GAIA plane. The information provided by the PROMETHEE-GAIA methodology is particularly useful for decision-makers to solve their decision problems. Two examples will support the presentation. Over 1200 papers related to PROMETHEE have been published up to now. One third of them are related to research on the subject, the others on applications. Some research results will be commented as well as some further possible research, especially in the fields of Ethics and System Dynamics.