THESIS ABSTRACT

Abstract

Selecting an appropriate procurement method was essential to the successful delivery of bridge construction projects, as it directly influences project performance across cost, time, quality, safety, stakeholder satisfaction, and long-term sustainability. This research analyzes the Design-Bid-Build (DBB) and Design-Build (DB) procurement methods used by the Department of Roads (DoR) in Nepal for bridge construction projects to evaluate their effects on overall project success. A quantitative research method was used, with a structured survey distributed to key stakeholders engaged in DoR bridge initiatives. The collected data was analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM) to assess the measurement and structural models and to investigate the relationships between procurement methods and project performance metrics. The results indicate that each procurement method significantly enhances project success; nonetheless, the DB approach shows a more pronounced overall impact (β = 0.736) compared to the DBB method (β = 0.482). The comprehensive DB method boosts collaboration among project stakeholders, strengthens integration of design and construction, minimizes interface conflicts, and achieves better results in design execution, upkeep and sustainability, defect liability management, cost efficiency, timeline performance, and stakeholder contentment. In contrast, the DBB method shows better performance in planning and design, procurement, quality, and safety owing to its organized planning process, autonomous oversight, and enhanced regulatory adherence. The findings suggest that the DB procurement approach offers improved efficiency and effectiveness for successful bridge project completion within the Department of Roads, Nepal.The research suggests improving procurement planning, contract management, risk distribution, and stakeholder collaboration to boost project outcomes. It promotes broader implementation of the Design-Build method for projects needing coordinated and prompt delivery, while maintaining the Design-Bid-Build approach for projects that require detailed planning and quality assurance. These results offer actionable recommendations for enhancing bridge procurement methods and the performance of infrastructure projects in Nepal.

Keywords

Procurement method, Project Success, Bridge Construction, Department of Roads (DoR), Design-Bid-Build (DBB), Design-Build (DB), Structural Equation Modeling (PLS-SEM).