Principles for a new family of outranking methods are given. The main aim of the proposed PROMETHEE approach is to be as easily understood as possible by the decision-maker. It is based on extensions of the notion of criterion. Six possible extensions are considered. These extensions can easily be identified by the decision-maker because the parameters to be defined (at most 2) have an economic significance. A valued outranking graph is constructed by using a preference index. Two possibilities are considered to solve the ranking problem by using this valued graph. PROMETHEE I provides a partial preorder and PROMETHEE II a total preorder on the set of the possible actions.multi criteria decision making