A heuristic for network project scheduling with random activity durations depending on the resource allocation

This paper presents a heuristic for resource-constrained network project scheduling. A PERT-type project, where activities require resources of various types with variable capacities,is considered. Each activity is of random duration depending on the resource amounts assigned to that activity. The problem is to minimize the expected project duration by determining for each activity its starting time and the assigned resource capacities. The resource project scheduling model is an NP-complete knapsack resource reallocation problem. To obtain a precise solution, a lookover algorithm has been developed. For the case when a lookover requires much computational time, an approximate heuristic algorithm is suggested. The problem has to be solved at each decision point, when at least more than one activities are ready to be operated but the available amount of resources is limited. The heuristic model is illustrated by a numerical example. (C) 1998 Elsevier Science B.V. All rights reserved.