Optimization Model of External Resource Allocation for Resource-Constrained Project Scheduling Problems

Construction project scheduling is crucial to project success. From the perspective of contractors, a practical schedule based on engineering experience not only improves the accuracy of project duration and cost estimation during the bidding process, but also facilitates the operation during project execution. This study employs Constraint Programming (CP) techniques to resolve resource-constrained project scheduling issues. A new scheduling model aiming for the minimization of total project cost, including resource usage and idle cost, is proposed in this paper. Most importantly, this paper introduces a new idea in resource-constrained project scheduling, namely the concept of external resources to enhance model feasibility for construction scheduling problems practice. A scheduling optimization engine coded in C++ is then developed to validate model feasibility and accuracy. The research results demonstrate the importance of external resources through case studies. Furthermore, the significance of critical resources is evaluated and discussed in this paper.