Multi-objective optimization for large-scale highway construction projects

The utilization of new incentive-based contracting methods in the construction industry has increased in recent years in order to motivate contractors to simultaneously minimize both the cost and duration of construction projects, while maximizing their quality. The application of these contracting methods requires construction planners to search for and identify optimal resource utilization plans that optimize project cost, duration, and quality. The main challenge in this optimization problem is identifying an optimal resource utilization option for each construction activity in the project from a set of feasible alternatives that lead to unique activity durations, costs and levels of quality. The availability of various resource utilization options at the activity level creates a very large number of possible combinations of resource utilization plans at the project level. The enumeration of all of these possible alternatives becomes computationally prohibitive for large projects especially that the number of these alternatives increases exponentially with the increase in the number of activities in the project. In order to overcome this major challenge and enable the optimization of project cost, time, and quality in large-scale highway construction projects, this study aims to: (1) develop a multi-objective optimization model for highway construction projects that is capable of searching for and identifying near optimal resource utilization plans that simultaneously optimize construction time, cost, and quality; (2) formulate a parallel computing framework that enables the optimization of real-life large-scale highway construction projects; and (3) develop a prototype automated multi-objective optimization system that integrates the research developments made in this thesis with available project management software applications to facilitate their ultimate use and adoption by the construction industry. The main research development of this study contribute to the advancement of current practice in highway construction planning and can lead to: (1) an increase in the efficiency of resource utilization in highway construction projects which can ultimately produce significant savings in public expenditures; (2) a reduction in the duration of highway construction and renovation projects leading to an accelerated revitalization of the currently aging highway system; and (3) an improved level of quality in newly constructed and renovated roads.