Solve scheduling problems with a fuzzy approach

Scheduling is a complex problem which occurs often in a manufacturing environment. Most of the available schedulers are based on a simulation approach using dispatching rules. These rules are often dedicated to the satisfaction of a single performance criterion, and are used whatever the characteristics of the system or the type of jobs, though scheduling is a multi-criteria problem. In this paper the scheduling problems are addressed using a non-classical approach supported by fuzzy control theory. The ability to deal with multi-variables makes fuzzy control a good alternative for the scheduling problems because it can easily make compromises among multi-criteria by properly combining elementary dispatching rules. These compromises can easily be adjusted in accordance with the objectives of the system and the characteristics of the jobs. The proposed method has been implemented and tested in a discrete event simulation environment. The results are presented in this paper.