Arnaud’s research project aims at developing a decision support system for the scheduling of the Sainte-Justine hospital’s operating rooms. Given the importance of the hospital’s surgery section, improving its efficiency would be synonym of a better quality care for the patients and of substantial economies for the hospital. The objective of this optimization is to minimize the amount of canceled cases and to maximize the use of resources. Moreover, the stochastic characteristic of the input data (surgery duration, available resources etc.) is inherent in the medical field and is therefore important to be taken into account. Thus, this problem is computationally challenging and needs operation research tools to be tackled in a acceptable amount of time.