JOBSHOP SCHEDULING WITH IMPRECISE DURATIONS - A FUZZY APPROACH

Jobshop scheduling problems are NP - hard problems. The durations in t he reality of manufacturing are often imprecise and the imprecision in data is very critical for the scheduling procedures. Therefore, the f uzzy approach, in the framework of the Dempster-Shafer theory, command s attention. The fuzzy numbers are considered as sets of possible prob abilistic distributions, After a review of some issues concerning fuzz y numbers, we discuss the determination of a unique optimal solution o f the problem and then we cast a meta-heuristic (simulated annealing-S A) to this particular framework for optimization, It should be stresse d that the obtained schedule remains feasible for all realizations of the operations durations.