“…Although many sorting methods using the concept of "outranking relation" have been proposed in the literature (see, e.g., Moscarola and Roy, 1977, Roy, 1981, Massaglia and Ostanello, 1991, Perny, 1998, Henriet, 2000, Norese and Viale, 2002, Doumpos and Zopounidis, 2004, Figueira et al, 2004, ELECTRE TRI appears to be the technique that has generated most studies (see Mousseau and S lowiński, 1998;Dias and Clímaco, 2000;Mousseau et al, 2001a;Dias et al, 2002;Ngo The and Mousseau, 2002;Lourenco and Costa, 2004;Tervonen et al, 2005;Dias and Mousseau, 2006) and applications (see, e.g., Andenmatten, 1995;Arondel and Girardin, 2000;Mousseau et al, 2000a;Moussa, 2001;Mousseau et al, 2001b;Roy, 2002;Georgopoulou et al, 2003). This motivates our study aiming at giving this method sound theoretical foundations.…”