Scheduling optimization of prefabricated construction projects by genetic algorithm

Published: 15 June 2021Prefabricated buildings are the direction of the future development of the construction industry and have received widespread attention. The effective execution of prefabricated construction project scheduling should consider resource constraints and the supply arrangement of prefabricated components. However, the traditional construction resource-constrained project scheduling implementation method cannot simultaneously consider the characteristics of the linkage between component production and on-site assembly construction. It cannot also fully adapt to the scheduling implementation method of the prefabricated construction projects. It is difficult to work out a reasonable project schedule and resource allocation table. In order to determine the relevant schedule parameters that can reflect the actual construction situation of the prefabricated building and meet the scheduling requirements of the prefabricated project, this study proposes a prefabricated construction project scheduling model that considers project resource constraints and prefabricated component supply constraints. Additionally, it improves the design of traditional genetic algorithms (GAs). Research results of the experimental calculation and engineering application show that the proposed project scheduling optimization model and GA are effective and practical, which can help project managers in effectively formulating prefabricated construction project scheduling plans, reasonably allocating resources, reducing completion time, and improving project performance.Linlin Xie, Yajiao Chen and Ruidong Chan

A note on time/cost tradeoff curve generation for project scheduling with multi-mode resource availability costs

Abstract: In this note we combine two known algorithms and show how they can be used in order to generate tradeoff curves between time and cost for deterministic project scheduling problems with multiple modes and resource availability costs. The approach can handle linear and non-linear non-decreasing cost functions and it is based on the exact algorithm presented in Demeulemeester (1995) for the resource availability cost problem without multiple modes. As the problem is NP-hard, the method is computationally viable to solve only problems of a moderate size. The performance of the combined algorithm is evaluated solving different problem instances generated by the software Progen, and the solutions are compared to the ones generated by a modeling language with the solver CPLEX