A Meta-analysis of Literature Comparing Project Performance between Design-Build (DB) and Design-Bid-Build (DBB) Delivery Systems

The design-build (DB) delivery system has been gaining popularity in the architecture, engineering, and construction (AEC) industry, in part because of the performance benefits it can offer to project stakeholders. Studies have been conducted to quantify these performance benefits in terms of commonly used metrics that include unit cost, cost growth, delivery speed, schedule growth, and project quality. This paper summarizes and organizes the construction literature that quantifies the differences in performance between DB and the more traditional design-bid-build (DBB) delivery system in terms of project cost, schedule, and quality. The paper discusses these findings in a meta-analysis format to uncover patterns, trends, or possible differences in the results. Interestingly, the study reveals that despite several research efforts, few present statistically significant comparative results for all key performance metrics. The paper contributes to the body of knowledge by summarizing two decades of DB performance research and identifying the range of project performance values that can be achieved using DB, which allows for an improved understanding of DB performance.