Policies and decision models for solving elective case Operating Room scheduling

Surgical cases constitute one of the most important activities in a hospital both from social and economics point of view. The most expensive facility involved in the surgical process is the Operating Room (OR), as it consumes between 10–15% of the budget in a hospital. Therefore, adequate decision-making for planning and scheduling ORs is of vital importance. This process can be decomposed in three phases: session panning problem (SPP), master surgical schedule (MSS) and elective case scheduling (ECS). In this paper, we focus on ECS, which serves to assign dates for surgery to all patients in the surgical unit's waiting list. In our model, patients must be operated before an exogenous deadline, while taking into account the different availability of surgeons. For this problem, we have developed a mixed integer programming model. We analyse two different policies corresponding to different surgical service models. In the P-S-OR policy, patients are first assigned to a surgeon and subsequently the set “patient-surgeon” is allocated to an OR shift. In the P-OR-S policy, patients are first assigned to an OR shift, and later a surgeon is assigned to each OR shift in the planning horizon. These two policies are tested using real surgical data from a surgical unit in a Spanish hospital. The results yielded by the P-OR-S policy suggest the latter to be more flexible than P-S-OR, as the patient doesn't have assigned a surgeon and therefore he/she does not depend on the surgeon's availability.