| Researchers and practitioners have been implementing 'lean' in the architecture engineering construction (AEC) industry since the 1990s. They seek to bring lean practices from the manufacturing and new product development communities, most notably those developed by Toyota, to the AEC industry in support of improved project delivery. Toyota engineers use a set-based design methodology to promote innovation in product design, reduce rework, and facilitate collaboration between project stakeholders. AEC practitioners use a set-based design methodology to some degree; however, it has not been formalized nor has implementation been widespread.;The set-based design methodology involves postponing commitment to a specific design, instead generating and evaluating sets of design alternatives. A design team reviews the sets of design alternatives available to each project stakeholder and integrates them to find compatible combinations. They weigh input from several project stakeholders at the same time, early on, and throughout project delivery, while studying tradeoffs between what individual stakeholders value and what is of value to the project as a whole. Set-based communication helps stakeholders avoid rework and, through teamwork, develop a more globally satisfactory design than would otherwise be the case.;This dissertation argues for the use of a set-based design methodology in the AEC industry and presents tools and processes that could aid in its implementation. It specifically explores the use of a set-based design methodology to select reinforcing steel (rebar) configurations for reinforced concrete projects through case studies and workshops. Moreover, it examines the role of the design structure matrix (DSM) in revealing opportunities for implementing a set-based design methodology and explains the role of the Choosing By Advantages Decisionmaking System (CBA) in a set-based design methodology.;Research findings illustrate the effectiveness of set-based design in reducing rework and facilitating innovation on AEC projects. No single set-based design methodology will apply to all projects: opportunities for implementation vary from project to project. This dissertation delivers a proof of concept for a set-based design methodology and validates it through case studies and workshops. Future research can deepen the theoretical understanding of set-based design methodologies and further advance tools to support it in the AEC industry. |
