A NEW AND EFFICIENT HEURISTIC FOR SCHEDULING PROJECTS WITH RESOURCE RESTRICTIONS AND MULTIPLE EXECUTION MODES

This paper presents a heuristic procedure for solving non-preemptive r esource-constrained project scheduling problems in which resources are limited but renewable from period to period. Associated with each act ivity is a set of possible durations and the corresponding resource re quirements, and the objective is to minimize the overall project durat ion. Unlike other heuristics that consider schedulable activities sepa rately and schedule only one activity at a time, the heuristic propose d in this paper enumerates some schedulable combinations of activities and chooses from them the one having the best value for an evaluation criterion. It is shown that, based on a set of 240 randomly generated problems, the proposed heuristic outperforms the best heuristics prop osed in the open literature up to the moment when this research was do ne.