title: Performance Comparison of Design-Bid-Build (DBB), Design-Build (DB) and Construction Management-At-Risk (CMAR) Methods, and Identification of Critical Success Factors for DB and CMAR in Water and Wastewater Projects
Creators: name: Shrestha, Shrijan
Publisher: name: University of Nevada, Las Vegas
publisherIdentifier: https://ror.org/0406gha72
publisherIdentifierScheme: ROR
Year: 2023

description: <p>The United States encounters numerous challenges within the water and wastewater sectors. The American Water Works Association mandates a capital investment of $1.3 trillion over the next 25 years for the restoration and renewal of water infrastructures throughout the United States. (AWWA). To design and construct cost-effective and time-efficient water and wastewater facilities without compromising the infrastructure quality, owners are adopting alternative approaches to project delivery like Construction Management-at-Risk (CMAR) and Design-Build (DB). These approaches introduce innovation and integration into project delivery, addressing specific limitations inherent in the traditional Design-Bid-Build (DBB) method. The rise in utilization of alternative delivery methodologies has prompted a necessity for evaluating their efficacy by means of performance assessment and comparative analysis regarding cost and time efficiency. While extensive comparisons have been conducted in the highway and building sectors, there is a paucity of research in the water and wastewater sectors regarding such analyses.Therefore, this study undertook a comparative assessment of cost and schedule performance within the water and wastewater sector, examining the DBB, DB, and CMAR methods. This was achieved through a statistical analysis using tangible hard cost and schedule data collected from water and wastewater utility owners, encompassing both public and private entities. The examination revealed that DB exhibited notably superior performance in schedule growth compared to DBB and CMAR. The outcomes of the cost and schedule analysis of three delivery methods can assist owners in making well-informed decisions regarding the selection of a delivery method based on their available time and budget constraints.</p><p>Given that alternative delivery methods are relatively new in the water and wastewater sector, utility owners lack the expertise and experience required for the successful implementation of these delivery methods. Thus, it is important to investigate the DB and CMAR methods’ critical success factors so that the projects can be completed within the scheduled time and budget with better quality. Hence, this research performed an exhaustive literature review on the critical success factors of the DB and CMAR methods. Subsequently, a survey was conducted among both public and private utility owners to rank these identified factors. The primary critical success factors (CSFs) identified in this investigation for maintaining budget and schedule adherence in Design Build (DB) projects within the water and wastewater domain include project team members possessing strong technical and planning skills, fostering mutual trust among team members, ensuring clear communication flow among project participants, the design-builder's adept combination of design expertise and construction techniques, competence, experience, and delegated authority of the design-builder's project team leader, prompt conflict resolution, and the owner's swift response to design-builder's requests and instructions. Conversely, the predominant critical success factors (CSFs) identified in this research for maintaining budget and schedule adherence in Construction Manager at Risk (CMAR) projects within the water and wastewater sector encompass the design consultant's capability to develop a sound design within budget and on schedule, the contractor's robust construction management proficiency, a clear communication flow among project participants, fostering mutual trust among the project team members, project team members exhibiting strong organizational, management, leadership, and control skills, incorporation of buildability by the design consultant in the design development, a construction leader's high commitment to achieving project goals, valuable input from the contractor, early involvement of the contractor in the design stage, swift conflict resolution, and prompt response from the consultant/owner to the contractor's requests and instructions. These findings can provide valuable guidance for water and wastewater utility owners, enabling them to prioritize these factors and effectively implement projects with a high degree of success.</p>