Reza Behmanesh - Department of Industrial Engineering, Science and Research Branch, Islamic Azad University Tehran, Iran
Mostafa Zandieh - Accounting and Management Faculty, Shahid Beheshti University
Seyed Mohammad Hajimolana - Department of Industrial Engineering, Science and Research Branch, Islamic Azad University Tehran, Iran

in this research, we address the surgical case scheduling (SCS) problem in order to minimize makespan. In surgical case scheduling, not only the hospital resources are allocated to surgical cases but also the start time of performingsurgeries is determined based on sequence of cases in a shortterm time horizon. Minimization of makespan for SCS is strongly Np-hard optimization problem; hence we employ ant colonyoptimization algorithms such as ant system (AS), ant colony system (ACS), and elitism ant system (EAS) so as to tackle this problem. Each algorithm is built in two-level comprise ofsequencing and allocating. These proposed approaches areillustrated by three test instances include of small, medium, and large dataset. Consequently, results of experiments indicate that ant colony system and elitism ant system outperform traditional ant system.

Surgical case scheduling problem; Ant system; Ant colony system; Elitism ant system;, Makespan