Fuzzy Evaluation of Alternatives-The Concept of Supporting Majority and Veto-Minority

The evaluation of alternatives plays a central role in optimization problems as the quality of solutions is judged depending on the outcomes of the chosen optimality criteria. Based on the relevant evaluation functions, optimization methods aim to identify solutions that are optimal, implying that these are considered to be favorable to the decision maker in a particular situation. In the current paper, existing approaches of evaluating alternatives are reviewed in the context of scheduling in manufacturing environments. Mono-criterion, multi-objective, as well as fuzzy approaches are reviewed. It is possible to observe limitations of traditional techniques that complicate the interpretation of the quality of solutions. To overcome the identified problems, a new evaluation concept is presented and discussed. It uses fuzzy set theory and fuzzy logic to derive a linguistic description of the qualitative characteristics of the alternatives, allowing the decision maker a close investigation of the solution properties in comparison to existing techniques. Although a specific problem domain is being targeted here, the implications are of general use for a broad range of optimization problems like course/ examination timetabling, vehicle routing, etc.