An integrated multi-objective optimization model for solving the construction time-cost trade-off problem

Abstract

As construction projects become larger and more diversified, various factors such as time, cost, quality, environment, and safety that need to be considered make it very difficult to make the final decision. This study was conducted to develop an integrated Multi-Objective Optimization (iMOO) model that provides the optimal solution set based on the concept of the Pareto front, through the following six steps: (1) problem statement; (2) definition of the optimization objectives; (3) establishment of the data structure; (4) standardization of the optimization objectives; (5) definition of the fitness function; and (6) introduction of the genetic algorithm. To evaluate the robustness and reliability of the proposed iMOO model, a case study on the construction time-cost trade-off problem was analyzed in terms of effectiveness and efficiency. The results of this study can be used: (1) to assess more than two optimization objectives, such as the initial investment cost, operation and maintenance cost, and CO₂ emission trading cost; (2) to take advantage of the weights as the real meanings; (3) to evaluate the four types of fitness functions; and (4) to expand into other areas such as the indoor air quality, materials, and energy use.

Keywords:

• multi-objective optimization
• pareto front
• non-dominated solution
• fitness function
• construction management

Additional information

Notes on contributors

Choongwan Koo

Choongwan KOO. He is a Post-doctoral Fellow at the Department of Architectural Engineering of Yonsei University, Seoul, Korea. He has received a PhD degree at Yonsei University. Before attending Yonsei University, he worked at international Construction Management company called ‘HanmiGlobal’ as a Research Engineer. His primary research areas include time and cost optimization for construction projects, building energy efficiency, new renewable energy, solar photovoltaics, carbon emissions reduction, life cycle cost, and life cycle assessment.

Taehoon Hong

Taehoon HONG. He has received a PhD degree at Purdue University. He is an Associate Professor at the Department of Architectural Engineering of Yonsei University, Seoul, Korea. He is an Editor-in-Chief in the Journal of Construction Engineering and Project Management, KICEM and a Corresponding Member of Editorial Board in the Journal of Management in Engineering, ASCE. Also, he is a member of academic or practical institute such as AIK, KSCE, ASCE, and KICEM. His main research areas include life cycle cost analysis, life cycle assessment, infrastructure asset management, facility management, and construction project cost control.

Sangbum Kim

Sangbum KIM. He is an Associate Professor at the Department of Civil and Environmental Engineering of Dongguk University, Seoul, Korea. He has received a PhD degree at University of Texas at Austin. Before joining the Doongguk University, he worked at Construction Industry Institute (CII). He has been helping the construction industry, especially in the area of productive analysis, construction contract and claim, information management and risk management. In particular, he has conducted extensive research funded by government organization such as Ministry Land, Transport and Maritime Affairs (MLTM).