Resource-Constrained Project Scheduling — Minimization of General Objective Functions

Abstract

In Chapter 2, we have dealt with project scheduling where the project duration or any regular objective function is to be minimized. Recall that a regular objective function is a function nondecreasing in the start times of activities. In practice, however, nonregular objective functions often occur as well. Examples of nonregular objectives are the maximization of the net present value of the project, where a positive or a negative cash flow is supposed to be associated with the completion of certain activities (net present value problem), the minimization of the earliness plus tardiness cost of the activities (earliness-tardiness problem), where a due date is prescribed for each activity, the minimization of the cost of resources purchased (resource investment problem), the minimization of the changeover times (changeover time problem), where sequence-dependent changeover times arise between the execution of consecutive activities, the minimization of a measure of the variation of resource utilization (resource levelling problem), and the minimization of the total renting cost of resources (resource renting problem).