DEBORA: a decision engine based on rational aggregation

Constraint propagation is a matter of logical deduction, but this is not always sufficient to reach a problem solution. Heuristic knowledge is usually needed to go on with the solution search when the first stage stops. The way this second type of knowledge is handled has more to do with decision rather than deduction process. In this paper the authors suggest a method to handle heuristic knowledge based on social choice theory. An analogy is proposed between the cooperation problem among heuristics expressed as decision rules and the voting problem. This analogy allows one to define and justify aggregation modes for results provided by each rule, with a view to providing a global decision ranking. An application to job-shop scheduling has been carried out