The Resource-Constrained Project Scheduling Problem with Work-Content Constraints

Abstract

For executing the activities of a project, one or several resources are required, which are in general scarce. Many resource-allocation methods assume that the usage of these resources by an activity is constant during execution; in practice, however, the project manager may vary resource usage by individual activities over time within prescribed bounds. This variation gives rise to the project scheduling problem which consists in allocating the scarce resources to the project activities over time such that the project duration is minimized, the total number of resource units allocated equals the prescribed work content of each activity, and precedence and various work-content-related constraints are met.

This chapter compares a priority-rule based method known from the literature against a recent MILP formulation on a benchmark test set of small-sized problem instances. Our computational results indicate that the priority-rule based method derives feasible solutions to all instances of the test set. The MILP formulation provides feasible solutions to a surprisingly large number of instances; most of these solutions are optimal or near-optimal, and on these instances the MILP formulation outperforms the priority-rule based method.