Cost-optimized transport planning for prefabricated modules with the implementation of the just-in-time strategy

Modular integrated construction (MiC) has witnessed increasing adoption in worldwide building projects, driven by various benefits, including improved construction efficiency, reduced on-site labor hours, and minimized waste and pollution. The construction industry has recognized the transportation of prefabricated modules as a huge obstacle to the wide implementation of MiC. In practice, transport planning of prefabricated modules is usually intuitively decided by general contractors based on experience. Intuitive decisions cannot ensure the just-in-time (JIT) module delivery, thereby incurring additional costs of early and late delivery. Motivated by this challenge, this study endeavors to design cost-minimized transportation plans for prefabricated modules using mathematical programming methodology. An integer programming model and a tailored solution method are proposed. Then, we use data from two real building projects in Hong Kong as model inputs to demonstrate the computation of optimal module transport plans using the proposed methodology. Numerical results show that, if the JIT strategy is not considered in module transport planning, the actual total transportation costs will be 21.74% higher than the expected ones. Comparative costs of JIT implementation and nonimplementation indicate the significance of the JIT strategy. Additionally, our proposed method can achieve punctual module delivery and reduce the overall transportation expenses by 10.13%, implying considerable cost savings.