A Mathematical Model for Scheduling Elective Surgeries for Minimizing the Waiting Times in Emergency Surgeries

Document Type : Original Article


1 Department of Industrial Engineering, Faculty of Industrial and Mechanical Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran

2 Department of Industrial Management, Management and Accounting Faculty, Shahid Beheshti University, Tehran, Iran

3 Faculty of Industrial Engineering, Golpayegan University of Technology, Golpayegan, Iran


The ever-increasing demands for surgeries and the limited resources force hospitals to have efficient management of resources, especially the expensive ones like operating rooms (ORs). Scheduling surgeries including sequencing them, assigning resources to them and determining their start times is a complicated task for hospital managers. Surgery referrals usually include elective surgeries that are admitted before the planning horizon of the schedule and emergency surgeries that arrive during this horizon and require fast services. In this paper, we presented a mathematical model for scheduling electives and emergencies. In our model, we considered surgeries as projects with multi-activities. We implemented the Break-in-Moments (BIMs) technique in this structure, which to our best knowledge has not been implemented in the literature before. We examined this method with real data from a medium-sized Norwegian hospital and observed that this method reduces the waiting time of emergencies to be inserted into the schedule without dedicating any OR merely to emergencies. In such a way, this method counterbalances between efficient OR usage and responsiveness for emergency surgeries.