A Bi-objective Model for Maximizing the Quality in Project Scheduling

Traditionally, the Resource Constrained Project Scheduling Problem (RCPSP) is investigated in the operations research literature from the makespan minimization perspective. However, a recent survey conducted in the United States revealed the surprizing fact that the majority of project planners consider maximization of the quality of project schedules as the most important objective (Icmeli Tukel and Rom, 1998). In this paper, the integration of quality in project scheduling is investigated. For that purpose, the problem is modeled as a bi-objective resource-constrained project scheduling problem. A new objective defined as the schedule robustness is introduced as a quality measure. The maximization of this objective is considered along with the makespan minimization. A tabu search algorithm is developped in order to generate an approximate set of efficient solutions. Several variants of the algorithm are tested and compared on a large set of benchmark problems. The results are analyzed using statistical design of experiments techniques.