Investigating the concept of integration in construction projects: Cases of integrated project delivery and design for manufacturing and assembly

This dissertation by articles aims to advance knowledge on the concept of integration in the construction industry, through recently emerged concepts, such as integrated project delivery (IPD) and design for manufacturing and assembly (DfMA). The construction industry is experiencing a paradigm shift from traditional transactional contractual methods toward more integrated, sustainable, and collaborative approaches such as IPD and DfMA. Recent global crises, such as the pandemic, global warming, and political conflicts, have led us to live in a new context, also known as the new normal. This has accelerated the shift in the construction industry, pushing it to adopt approaches that eliminate waste and add more value to construction projects. Many researchers have highlighted the substantial impact of integrative and collaborative approaches on improving construction projects performance; however, their implementation remains rare and poorly documented. Still few practitioners and organizations seem committed to adopting these advanced integration strategies. Accordingly, academic research can certainly play a positive role and facilitate their understanding and implementation by the industry practitioners. In this context, first, we selected integrated project delivery (IPD) as the most recent collaborative delivery method and tried to understand (a) what integration in the context of IPD is and what the IPD integration mechanisms are, (b) what the contractual, organizational, and operational characteristics of IPD are which allow integration mechanisms to be implemented in construction projects, and (c) how IPD can address the new-normal challenges in the construction industry through its characteristics. Then, we selected design for manufacturing and assembly (DfMA) as a collaborative strategy that supports the implementation of IPD and conducted studies on (d) how the interplay between IPD and integrated design strategies such as design for manufacturing and assembly (DfMA) can improve the current status of construction projects. Based on four journal papers, that are either submitted, in revision, or published, this thesis aims to answer these questions and contribute the body of knowledge, by conducting various conceptual and empirical studies about IPD. Accordingly, in the first article, the concept of “integration” in IPD literature is studied and implementation strategies that can positively contribute to construction projects are identified. All IPD integrating techniques cited in the literature were extracted, and their integration dimensions (strength, scope, duration, and depth) and directions (vertical, horizontal, and longitudinal) were discussed in three contexts: (i) on-site construction projects, delivered traditionally, (ii) on-site construction projects, delivered through IPD, and (iii) off-site construction projects, delivered through IPD. The results showed that applying IPD in off-site construction projects creates complete vertical, horizontal, and longitudinal supply-chain integrations during the projects’ life cycle, which can reduce the project duration. In the second article, a systematic literature review is conducted to identify the most recent IPD research themes and future trends. Results showed that the most prominent emerging research themes from the literature are identified as: technological and procedural under the operational-cognitive cluster; legal and commercial under the contractualregulative cluster; and cultural/behavioral and structural under the organizational-structural cluster. In the third article, various challenges encountered by construction projects after the pandemic era are extracted from the literature and classified into three stages: pre-construction, construction, and post-construction. Then, two Canadian case studies are conducted to collect data and validate the results of the review. Several focus group discussions and interviews were also conducted with projects stakeholders, in which IPD principles were discussed, and study participants were inter iewed to list principles that could address the new-normal challenges. The results showed that the number of IPD principles that have been applied in case study projects has increased since the beginning of the pandemic. The IPD principles that are the most applied in the new-normal era relate to the technological (integrating technologies, digital platforms, cloud-based and web-based technologies) and relational aspects of IPD (multiparty alliance, cluster-based management, and shared risks/rewards. In the fourth article, an integrated design and construction strategy, which is called design for manufacturing and assembly (DfMA), is investigated to understand how the interplay between integrated delivery and business models such as IPD and DfMA can enhance integration in construction projects. First, a systematic literature review and several focus group discussions are conducted, to identify challenges of applying DfMA method in construction projects, and categorize them into 8 categories: contractual, technological, procedural, cultural, commercial, geographical, financial, and technical/cognitive. The results show that the majority of identified challenges were related to the contractual and operational aspects of construction projects and the associated stakeholders. Next, a construction-oriented DfMA (C-DfMA) framework to address the identified challenges is developed, based on an interplay between DfMA, integrated business models, relational and integrated delivery methods, and lean-based operational tools and technologies. The results show that the synergistic impact between integrated and collaborative strategies, such as IPD, DfMA, and lean-based operational techniques can create a suitable environment for addressing current construction industry challenges that are mostly due to fragmentation. The articles proposed in this thesis aim to provide theoretical and empirical insight into the concepts of great interest to the construction industry, and in doing so, sensitize the practitioners in the field to engage more efficiently in their implementation.