Multi-period and multi-resource operating room scheduling and rescheduling using a rolling horizon approach: a case study

In this paper, a multi-period and multi-resource operating room (OR) scheduling and rescheduling problem with elective and semi-elective (semi-urgent) patients is addressed. A scheduling-rescheduling framework based on the so-called rolling horizon approach is proposed to solve the problem. The core of the proposed framework is a novel proposed mixed-integer linear programming (MILP) model with the objectives of minimizing tardiness, idle time and overtime. Pre-operative holding unit beds and recovery beds as important resources in surgery departments are taken into account. At first, a schedule is set for all of the days of the planning period. Then, at each iteration, the scheduled patients are fixed (frozen) for the first day of the planning period and a rescheduling is done due to arrival of the semi-urgent patients. Then the planning period is shifted. This process continues until all days of the planning horizon are covered. Numerical analysis and comparisons are done between the proposed approach and two scenarios which are applied in many hospitals. In the first scenario, the semi-urgent patients would be operated in the first available OR after operating elective patients and in another scenario, a specified amount of capacity is allocated for semi-elective patients. The outcomes conclude that the proposed method has much better performance and also statistical test supports this superiority. Finally, a case study is implemented in a hospital in Iran. Numerical analysis shows that our proposed approach surpasses the actual schedule of hospital significantly.