IDAMS module Rank comprises three programs; of these, one is based on classical
logic (Electre), whereas the other two programs are based on fuzzy logic (Fuzzy
method–1 and Fuzzy method–2). The first fuzzy method was originally
proposed by Orlovsky for solving decision making problems with fuzzy information.
This method was modified by Hunya to adapt to the problems in which alternatives
have to be ranked on the basis of a collective opinion. This adaptation makes
it possible to find a sequence of non–dominated layers (or cores) of alternatives
in a fuzzy preference relational structure, which does not necessarily represent
a total linear order. The second fuzzy method was developed by Skofenko. This
method tries to find the credibility of all prepositions: "the *j*^{th}
alternative is exactly at the *p*^{th} position in the rank–order"
These methods are briefly described below.