Considering the complete process of surgery including the

preoperative and postoperative stages, multiple resource constraints involved and

the integration of surgical upstream and downstream resources, surgery

scheduling was described as an extended multi-resource constrained flexible

job-shop scheduling problem and an optimization approach was proposed based

on an improved ant colony algorithm. A resource selection rule and strategy of

overtime judging and adjusting was designed, and the scheduling process with

the ant colony algorithm was realized. The case study shows that the improved

ant colony algorithm proposed in this paper achieved good results in shortening

total time and allocating resources for surgery scheduling