GenDI
Method
Outranking methods that compare alternatives through concordance and discordance, allowing “incomparable” instead of forcing everything onto one score.
The founder
1934–2017 · Université Paris-Dauphine
The father of the European “outranking” school of decision aiding and founder of the LAMSADE lab. In the 1960s he created ELECTRE, arguing that sometimes two options are simply incomparable, and a good method should say so rather than fake a winner.
The idea
In five steps
Criteria & weights
Set criteria and their importance.
Concordance
Coalition of criteria backing a over b.
Discordance
Criteria strongly opposing it (veto).
Outranking
a outranks b if backed and not vetoed.
Exploit
Rank or choose from the relation.
The share of criteria (by weight) that agree “a is at least as good as b.” High concordance supports an outranking.
If a single criterion is far too against it, a veto blocks the outranking, no matter how strong the rest.
Compare with confidence.
Let GenDI weigh the trade-offs your decision can't ignore.
Roy, B. (1991). The outranking approach and the foundations of ELECTRE methods. Theory and Decision, 31, 49–73.