Heuristics for scheduling projects with resource restrictions and several resource-duration modes

The problem addressed in this paper is the non-preemptive resource-constrained project scheduling problem in which the duration of each activity depends on the amount of resources allocated to its execution, and the objective is to minimize the overall project duration. It is also assumed that resources are limited but renewable from period to period. Twenty-one heuristic scheduling rules are compared on 240 test problems divided into two main groups containing 50 and 100 activities, respectively. Each group contains one-resource, two-resource and four-resource problems. The results of the comparative study allow us to identify the most efficient heuristics and suggest a combination of five-heuristics which have a high probability (229 over 240) of giving the best (among the 21 solutions obtained) solution.