Modeling and solving multi-site scheduling problems

Multi-site scheduling deals with the scheduling problems of an enterprise with several distributed production sites, where sites are using the intermediate products of the other sites to manufacture the products of the enterprise, e.g. in car or airplane manufacturing. In the multi site-scheduling scenario we differentiate between a global and a local scheduling level. On the global level a global schedule is generated providing the requirements for the local level schedulers. The local schedulers then have to transform the global schedule into a concrete local schedule for manufacturing. Different goals have to be regarded on the different levels. In case of unforeseen events rescheduling and manual interaction is necessary on both levels. Due to the distribution of the problem to several units scheduling as well as coordination problems have to be solved. This paper presents an approach that adopts modeling and problem solving techniques used for local scheduling problems for the new global scheduling problems. Additionally, specific problems are solved by new approaches, e.g., coordination using a blackboard, heuristic and fuzzy techniques dealing with the highly dynamic environment and the imprecise knowledge. The multi-site scheduling problem as well as selected results of the approaches on the different levels will be presented.