Principles of Sequencing and Scheduling, 2nd Edition

17Resource‐Constrained Project Scheduling

17.1 Introduction

In this chapter, we synthesize much of the previous material to address the deterministic resource‐constrained project scheduling model. Later we discuss stochastic counterpart models, briefly. Recall from Chapter 1 that scheduling decisions are generally subject to both precedence constraints and resource constraints. The resource‐constrained project scheduling model contains both types of constraints. The preceding chapters have dealt with a variety of situations in which one or both of these types of constraints are relaxed or at least simplified. In a sense, the difficulties in those simpler problems are superimposed in resource‐constrained project scheduling.

A general precedence structure accommodates arbitrary precedence constraints, such as those found in the network models of Chapter 16. In that analysis, however, the critical path calculations assume that resources of the appropriate type and amount are sufficiently available, so resource capacities are never binding on scheduling decisions. Chapter 8 covered some problems involving precedence constraints, but with only one resource (machine). In flow shop and job shop problems, where more general resource models apply, precedence relations are restricted to special structures.

A general resource structure contains multiple units of each of several different resources. Chapter 9 introduced models with resource parallelism but only for one resource type, and ...