Complex sentence: He has worked on the graph theory and on multiple criteria decision aiding, having created the ELECTRE methods, stands for "ELimination Et Choix Traduisant la REalité".
Split into simpler sentences: He has worked on graph theory and on multi-criteria decision analysis (MCDA), having created the ELECTRE family of methods. ELECTRE stands for "ELimination Et Choix Traduisant la REalité".