A Comparison of Exact Approaches for Solving the Multiple Constrained Resource, Project Scheduling Problem

TLDR

Project scheduling must resolve resource conflicts by allocating scarce resources to activities, aiming to minimize the resulting increase in project duration. This paper examines procedures that provide decision support for resolving such resource conflicts. The procedures are enumerative, systematically exploring partial schedules while using different tree generation, storage, and pruning strategies to avoid evaluating all possibilities. Each procedure proved generally superior on a particular class of problems, and those classes were identified.

Abstract

A recurring problem in managing project activity involves the allocation of scarce resources to the individual activities comprising the project Resource conflict resolution decisions must be made whenever the concurrent demand for resources by the competing activities of a project exceeds resource availability. When these resource conflict resolution decisions arise, project managers seek direction on which activities to schedule and which to delay in order that the resulting increase in project duration is the minimum that can be achieved with the given resource availabilities. The procedures examined in this paper are all designed to provide for this type of decision support. Each procedure examined is enumerative based, methodically searching the set of possible solutions in such a way that not all possibilities need be considered individually. The methods differ in the manner in which the tree representing partial schedules is generated and is saved, and differ in the methods which are used to identify and discard inferior partial schedules. Each procedure was found to be generally superior on a specific class of problems, and these classes are identified.