A trend towards a more relational type of contracting can be noticed in the Dutch infrastructure industry. These so-called relational project delivery models are supposed to deal with the current challenges of regular cost and time overruns, the growing demand and the adverse relationship between contractor and client in traditional projects, leading to an unfair risk allocation, lack of collaboration and lots of conflicts. One of these measures proposed by RWS is the introduction of the two-phase model. For specifically the first phase it is unclear how the collaboration can be improved and how a collaborative identity might contribute. The research question therefore is: How could the first phase of the two-phase model in infrastructure projects in the Netherlands be organized to improve collaboration and how does the formation of a collaborative identity contribute to this? A further operationalization of collaborative identity resulted in a definition: An identity within the project that distinguishes the organization and contributes to a collaborative mindset in the project organization. Improved collaboration can be achieved by implementing certain principles in the project by the organization of specific working practices. These working practices and principles were gathered from different streams of literature such as the alliance, early contractor involvement and bouwteam models. The principles are scored on their importance to collaboration in the first phase of the two phase model and the working practices were scored on their contribution to achieving the principles. This resulted in a framework identifying the most important principles and working practices. This framework was then discussed with two separate focus groups from the contractor and the client. The comments and discussion was used to update and improve the framework. The framework is found in figure A. The most important conclusions were to apply the framework in a so called project start up. Furthermore a shared vision and objectives related to the project are important for the two-phase model, as two organizations should collaborate intensively in the first phase, while the price is not yet set. Involving the right people who can work in this ‘new’ way in the project is vital, and the price should be constructed using open book, and avoiding fixed price elements in the tender phase. Finally it is concluded that the collaboration in any project should be an active project goal. This means that effort should be made to evaluate, discuss and reward behaviour resulting in good collaboration. The conclusions indicate the importance of a collaborative identity to the collaboration in the first phase of the two phase model and this was also specifically confirmed by the participants of the focus group. For future research it is recommended to perform more research on collaborative identity. Secondly more research should be performed on the two-phase model, when the projects have been finished, also relating to the success of the overall project. Finally research on the collaboration in the second phase and the transition from the first to the second phase should be performed.

Circular Economy (CE) is a new economic development paradigm that is proposed as a counterweight to the traditional “take, make, use and dispose” model, known as Linear Economy (LE). To cope with the increasingly environmental impact of construction, a transition towards CE can be the solution. To that direction, several circular initiatives in the Netherlands, have provided an array of circular infrastructure projects that have been completed or are near completion. Scholars and practitioners alike have pinpointed the significance of inter-organizational collaboration, in the development of circular projects. However, this field is inadequately researched. This research investigates collaboration, under the prism of governance, defined as the set of rules and procedures, that govern the collaboration in the project environment. The aim of this study is to identify the governance arrangements that are in place in circular infrastructure projects and provide a framework of governance that could resolve known collaboration challenges. To that direction, first a literature review is conducted, to identify governance arrangements, based on the literature on inter-organizational, network and collaborative governance and collaboration in the circular economy. The findings are utilized to develop a research framework. This framework is validated through a multiple case study, where 14 participants across 3 circular infrastructure projects are interviewed regarding the governance arrangements that are in place. As a result, an elaborated framework of governance for circular infrastructure projects is proposed. The framework contains governance arrangements across 7 different dimensions of governance, namely Goal Setting, Rewarding, Monitoring, Capability Building, Roles and Decision Making, Coordination and Motivation. Lastly, through this research recommendations towards practitioners on the field of circular infrastructure are given. Those include: Making a clear distinction between circular project and circular sector, Developing circular projects as a way to alter the sector, Generating and sharing knowledge, Investigate the capabilities of actors and select partners based on their skills and motivation, Utilize traditional forms of collaboration when the necessary capabilities are absent, Consider reputation and future business opportunities as the main incentive for participation in circular infrastructure projects, and Achieve external support through cultivating an intra- organizational circular mindset, showcasing results and achieving positive reputation.

There is no argument against the need to achieve other value types in infrastructure projects to meet the actors' expectations and broader organizational goals. The value engineering approach, later adjusted under the term 'value management,' achieves desired functions at the lowest cost through a set of workshop activities. Integrating value engineering with benefits management could expand what value means and identify additional value. However, benefits management has limited applicability to infrastructure projects due to inconsistent definitions and perceptions regarding value creation as well as its literature lacks an understanding of the appropriate governance mechanisms. Consequently, this study aims to explore how integrating value engineering with benefits management can help practitioners consider value more holistically in infrastructure projects by answering four sub-questions that aim to explore value engineering and benefits management, conceptualize governance mechanisms, assess how value engineering is currently conducted in built environment projects, and identify steps practitioners can take to expand the integration of these methods. The cases' workshop activities were structured into seven phases: preparation, information, function analysis, creative, evaluation, development, and presentation. The governance mechanisms used included coordination, building-capability, goal-setting, monitoring, and roles & decision-making. Based on both theoretical and empirical results, the developed project governance process involves several workshop activities and governance mechanisms, where value is defined in terms of impact and then working backwards through a multi-phase process. The process is divided into the following phases: usefulness & necessity phase, preparation phase, information phase, outcome and impact analysis phase, creative phase, evaluation phase, development phase, and presentation and reporting phases. A visual representation of this process can be seen in Figure 4.1 in the original document. Once developed, a workshop confirmed its feasibility for implementation because all phases were clearly explained. Experts' recommendations included linking these phases with work packages, conducting risk analysis before the "creative phase," and making it more visually appealing through a flowchart full of icons or colors to help technical actors better understand it and thus make it more practical. Integrating the benefits management and value engineering approaches can be achieved by incorporating them into the already-established value engineering multi-phase process. This requires considering all scales along which value evolves, starting from impact, and evaluating them once identified. By doing so, actors are equipped to take more parameters into account, mitigating the uncertainty between expected and realized value. Additionally, governance mechanisms play a crucial role in aligning all actors' expectations towards achieving high-value goals by bringing them together towards a shared goal.

The circular economy in the construction sector aims to lessen the environmental impact of construction projects by incorporating the end-of-life phase into the design and the conscious use of reusable resources. To achieve a circular economy in the built environment, it has been evidenced in the literature and practice that governance mechanisms in inter-organizational collaboration are required between the multiple parties involved to quickly rethink the purpose of the project, the desired outcome, and the aligned efforts towards the solutions of circular challenges. This research gains insight into the governance mechanisms that have proven to be desirable or beneficial in the collaboration between public clients and main contractors during the front-end phase in building projects with circular values. It is accomplished through two stages: (1) a comprehensive literature review was conducted where 25 articles were selected based on keywords related to inter-organizational collaboration. It brought the most representative knowledge of the existing forms and types of collaboration on construction projects, as well as an existing framework created to analyze the approaches for coordination, adaptation, and safeguarding of exchanges between the focal parties of inter-organizational projects. The literature included a second search of current circular practices in construction projects; (2) a multiple-case study strategy was conducted to explore how the inter-organizational collaboration between public clients and contractors was governed toward the delivery of circular building projects. Data was collected from publicly available documents and semi-structured interviews on the three cases that shared the most similar approach based on applied circular practices. This study's result contributes to the current literature and practice by asserting that governance mechanisms in inter-organizational collaboration between public clients and main contractors facilitate the adoption and implementation of circular practices in building projects. The results expressed that relational and contractual governance mechanisms complement one another in goal-setting, capability building, roles and decision-making, rewarding, coordination, and monitoring. Various governance mechanisms within each of these dimensions can be employed to pursue circular practices under specific contexts, thereby supporting the transition to a circular economy in building projects.

As a result of the high failure costs and many project delays in the construction industry, collaborative contracts emerged in an attempt to improve project performance. The project alliance was one of them. This integrative way of working requires a focus on the human aspects, because people from different organisational cultures are brought together, but this is not the case in practice. One of these human aspects is the formation of a collaborative identity.A collaborative identity refers to the collaborative values and working practices that form the organisational self-image and differentiates the organisations from others. It provides a feeling of belonging for each individual within the project alliance. The collaborative values and working practices that are required to build a collaborative identity are unknown, and therefore this research answers the question "How can collaboration within a project alliance be improved through a focus on the formation of collaborative identity?". The research is performed by means of a literature study as well as a Delphi study with two participating project alliances. The main outcome of the research was that forming a collaborative identity requires a different combination of working practices and collaborative values, that were defined during this research, for different project alliances.

One of the reasons for the failure of large infrastructure projects is the increasing complexity of such projects. Complexity is considered a source of risks. These risks can be negative, called threats, or positive, called opportunities. The current risk management process implemented in practice mainly deals with threats, and opportunities are almost not considered. This research aims to study how individuals involved in complex infrastructure projects can better set the scene for opportunity management and capitalize on the opportunities that complexities offer. First, a literature study was conducted to define the relevant concepts such as project complexity and opportunity management. Next, to understand the current approach of identifying opportunities in practice, interviews with practitioners in the field of infrastructure were conducted. After that, the aim was to study the possibility of exploiting complexities. This was achieved by organizing a workshop session, where four Project Managers collaborated to identify opportunities, in four infrastructure projects, that result from the technical (T), organizational (O) and external (E) complexity elements of the TOE framework developed by Bosch-Rekveldt et al. (2011). As a result, a technique that aims particularly at identifying the opportunities that emerge from the complexities was developed: the Complexity-Driven Opportunity Identification Technique (CDOIT). Finally, this technique was integrated in a roadmap that aims for the effective implementation of opportunity management in complex infrastructure projects. This study suggests having a common understanding among the project team of the concept of opportunity as a positive risk and how it is linked to the project objectives. These objectives should be clearly stated from the beginning of the project. Also, if the team is determined to identify and manage opportunities, and even more, the opportunities that result from the complexity of the project, this should be clear from the start and included in the risk management plan (RMP). Another important factor is to determine the people who should be involved in identifying opportunities. Furthermore, the techniques that can facilitate the identification of opportunities and how these will be assessed, handled and monitored should be determined. Also, individuals looking for opportunities should be equipped with the right positive mindset. This will help in switching from a threat-focused mindset to a mindset that focuses on the positive side of risk. This study also proposed five possibilities into how complexities can be exploited. This can be done using internal strengths, taking advantage of external weaknesses combined with internal strengths, aiming to turn internal weaknesses to strengths, through a better use of available resources, and by increasing the scope of the project.