Hierarchical scheduling for decision support

The paper proposes a two-level scheduling structure based on time aggregation. One of the main purposes of the upper-level module is to balance the load and optimally distribute production over a medium-term time horizon. Another basic objective of this module is to help the decision maker in the choice of managerial decisions related to overtime work, subcontracting, backlogs. The main role of the lower level is to implement the upper-level decisions as efficiently as possible. The study validates feasibility, robustness and efficiency of the proposed two-level structure. Experiments on real data show that the two-level structure generates substantial improvements of the schedule, particularly by decreasing the number of late jobs. [PUBLICATION ABSTRACT]