This thesis addresses a central challenge in infrastructure project management: despite sophisticated monitoring tools like Earned Value Management (EVM), teams struggle to proactively identify and address root causes of performance deviations. The research investigates why EVM-based systems often fail to deliver actionable insights and explores whether integrating Root Cause Analysis (RCA) with Bayesian-enhanced EVM can bridge this gap. Anchored in a large infrastructure project at Schiphol Airport, the study combines literature review, interviews, Bayesian modelling in GeNIe, and validation with industry stakeholders. The findings present a dual-layer framework: (1) a Bayesian Network linking performance indicators (SPI, CPI) to risk drivers, enabling backward reasoning from deviations to causes, and (2) integration of RCA to reveal systemic factors behind disruptions. Validation confirmed the tool’s conceptual usefulness but highlighted adoption challenges, including dashboard integration, model complexity, and cultural readiness. The research concludes that embedding RCA into Bayesian-enhanced EVM shifts it from a reactive tool to a forward-looking enabler of organizational learning. However, technical robustness must be complemented by openness, accountability, and a culture of learning. Recommendations include piloting in mid-complexity projects, calibration with real data, and building scenario libraries from historical RCA cases. Overall, the work reframes risk management as a dynamic, learning-oriented process, emphasizing that better project outcomes rely not only on better data, but also on diagnosis, culture, and collaborative decision-making

Public participation is increasingly central to infrastructure planning in the Netherlands, evolving from consultation to integrated governance (Alpkokin, 2012; Bobbio, 2019). The Environmental Act, introduced in 2024, aims to simplify regulation, promote early stakeholder involvement, and enable local customization in spatial development (T. Kamer der Staten-Generaal, 2013a). By embedding participation into law, it seeks to improve decision-making quality, increase support, and reduce objections.

This shift reframes participation as a shared task between governments, contractors, and citizens. Contractors now operate within a governance model that emphasizes trust, flexibility, and societal value (Verweij et al., 2022). Their responsibilities in stakeholder engagement and environmental coordination are expanding, particularly during project realization. However, while early-phase participation has been widely studied, its role during the realization phase remains underexplored.
The main research question: How does the Environmental Act impact public participation during the realization phase of infrastructure projects, particularly for contractors?
To answer this, a qualitative design was used, combining a literature review, exploratory interviews, three case studies and an expert evaluation.

The findings show that the Act has not yet transformed participation during the realization phase. Participation remains largely procedural, focused on communication and compliance, with limited opportunities for stakeholder influence. Contractors often join after key decisions have been made, reinforcing an instrumental use of participation, more about risk management than co-creation.
While the contractor’s role is evolving, constraints such as late involvement, fixed contracts, limited resources, and unclear mandates hinder meaningful participation. Changes are mostly seen at the level of procedures and reporting (second-order governance), whereas deeper institutional shifts, trust, shared values, and clear role divisions (third-order governance) are lacking.
To bridge this gap, several improvements are needed: earlier contractor involvement, better role clarity, and flexible contract models that allow for participatory adaptation. Without such reforms, participation risks remaining symbolic. Contractors stepping into public roles must also embrace the societal value of participation—focusing not just on compliance, but on legitimacy, inclusiveness, and sustainability.
Limitations include the recent implementation of the Act, limiting observation to short-term expectations. The small number of cases reduces generalizability, and citizen perspectives are underrepresented. In addition, ambiguity in the definition of “participation” and variation in procurement practices create challenges in interpretation and execution.
In conclusion, the Environmental Act represents a symbolic but conditional shift. Its real potential depends on institutional alignment and a proactive, shared commitment to participation. For contractors, this means investing in stakeholder skills, integrating participation into planning, and engaging early with clients. Public authorities, in turn, must enable this by offering flexible procurement structures and clear accountability frameworks.
Future research should explore: long-term behavioural change, contractor adaptation, contract impacts on participation quality, and ways to reduce bureaucratisation without compromising participatory value.

Projects are becoming larger and more complex, resulting in work being done more in a team environment. Among other industries, the construction industry is project-based as well. For the successful completion of construction projects, inter-organizational teams consisting of representatives from the owner, designer, contractors and other stakeholders need to cooperate. Due to the numerous relationships between the various organizations, construction management faces great challenges. One of these challenges is the encouragement of information sharing. Thus, information sharing in inter-organizational projects has already concerned academia for a long time. However, knowledge of how information flows during the design life-cycle is still limited, and no study has been found to examine that by using social network analysis.

Therefore, this research adopted social network theory to study information flows as its main research activity. By gathering data through a survey and analysing them by performing social network analysis, it was possible to map the communication network of the inter-organizational venture by creating sociograms and extracting some key metrics that would give meaning to these. In parallel with the social network analysis, some participant observations added a qualitative character to how information flowed between the teams. However, these two research activities were insufficient due to some limitations this study was subjected. Thus, the results from the already mentioned research activities were enriched by hosting an expert panel where the experts invited could provide further insights into the networks’ formation.

This research concluded that in the predesign phase, there should have been more involvement from teams that were generating valuable information to balance the control that the most influential team, according to the SNA, had over the flow of information. The different design teams should have had the same degree centrality and probably the same betweenness centrality. However, it may also be the case that one area is more complex and more information-dependent, thus ranking higher in terms of influence in the network. In the definitive design phase, team Management Design & Integration should control the flow of information. However, other teams should also support it since being the only one to have control may become a bottleneck or even a single point of failure. Such teams could be teams of the same subculture regarding their roles and responsibilities in the organization. In the execution-ready design phase, many central figures concerning the construction-related teams exist in the network since many activities take place. There are multiple sources of information; thus, team Management Design & Integration should be able to absorb all of it. Attention must be paid to the various barriers that have been found to impact how information flows. Especially in how the information is being communicated and how to motivate employees to use the various technological developments available since they found to enhance information sharing.

In modern construction, collaboration has become a key element for the success of projects. Both clients and contractors are aware of the importance of maintaining a solid relationship. However, as collaboration is subject to ambiguous factors that influence both the content of the project and the social elements, it is proven to be difficult to achieve this mission. Elemental differences in the goals, ambitions and responsibilities of clients and contractors during projects still exist and cause differences in perception. One of the elements collaborations are subject to, are external factors. These are especially hard to deal with due to the fact that the occurrence of said factors is beyond the control of the project team. This research provides insight in this volatile environment with the aim to increase the resilience of collaborations by answering the question: “What external factors are present during construction projects that influence the collaboration between client and contractors and how can the impact of these events be reduced up-front?”. To answer this question, a Q-study is performed. As input for this study, a model of the project environment distinguishing the internal and external project environment is created. The model defines 8 domains of external factors which influence client-contractor collaboration: economic, technological and political -context, the parent organisation of both client and contractor, subcontractors, related projects & surroundings and lastly the stakeholders. From the Q-study four perspectives on external factors are retrieved, confirming the difference in perception of the external factors for individuals, based on their respective role and organisations in the collaboration. To reduce the influence of external factors on the dynamics within the project team, a framework of measures to create resilient collaborations is composed. The measures are divided in three categories: preliminary organisation, creating flexibility and attention to soft side. Each category is elaborated on with specific measures and which domains are addressed by implementing these measures. Moreover, the implementation in the project life cycle is explained making the framework directly usable for project organisations.

This research aims to overcome risk aversion by optimizing the allocation of risks in projects procured through an Innovation partnership. The research question answers: How can an Innovation Partnership stimulate innovation in the construction industry by dealing with uncertainties related to product innovation? The relevance of this research lies with the need for innovation in the construction industry to meet future sustainability and circularity goals and to renovate and replace existing infrastructure. However, due to the novelty of innovation, more uncertainty is introduced in a project where innovation is included. To stimulate innovation through an Innovation Partnership, the contractor and the contracting authority should manage the uncertainties related to product innovations following the level of uncertainties of the product innovation in the specific project stages. The level of uncertainty surrounding a product innovation reduces after the R&D phase of the Innovation Partnership. Therefore the contractor and the contracting authority should distinguish a difference between the R&D phase and the execution phase of an Innovation Partnership. It is recommended that when the contracting authority procures a project through an innovation partnership (1) they minimize the number of specifications and state the specification functionally to utilize the innovativeness of the market. (2) Stakeholders should be engaged in the project early on to overcome the resistance of stakeholders that are not ready for innovation. (3) The risks during the R&D phase should be managed by a design alliance. (4) The execution phase can be governed by an UAV-GC for the general project. In addition, an alliance module should be added for the risks related to the product innovation.

Public Private Partnerships (PPPs) are currently the desired project delivery method for big infrastructure projects in the Netherlands. PPPs contain a lot of contact moments between both organizations. Contractors encountered the problem that not all contact moments create public or private value, some might cause a loss of value. This thesis researched this phenomenon and looked for optimizations to these contact moments to create more (public and private) value. The thesis did so by doing a case study on three Dutch DBFM infrastructure cases. The thesis conducted interviews with high-ranked managers of both the clients and contractors of the three cases to gain insights from both sides. The results of the subsequent qualitative content analysis showed that contact moments can be optimized to create more value in three different ways. The first is by introducing so called 'collaboration programs'. This program contains deep and frequent meetings between both the public and private organization where discussions on personal matters and soft factors take place, as well as workshops on these topics. The second optimization is to improve the contact moment structure of DBFM projects. This can be done by: having daily informal contact moments and bi-weekly or monthly formal contact moments, have easy access to informal contact moments by being in the same or adjacent buildings, have frequent BOT-meetings, Project Start-Ups and Project Follow-Ups. The third optimization is to improve single contact moments. This can be done by doing good preparations, defining a goal and evaluate the contact moment at its end.

Construction projects are argued to be the most complex of all production undertakings (Baccarini, 1996). Williams (2002, 2005) states that the complexity of these projects is a contributing factor to project failures, such as cost overrun, which are commonly seen in infrastructure project (Cantarelli, Molin, Van Wee, & Flyvbjerg, 2012). As one of the first Morris & Hough (1988) describe that cost overruns are common and that many projects appear as failures, while Flyvbjerg et al. (2003) agrees with Morris & Hough, by stating that this is a long-lasting problem since cost estimates have not improved and cost escalations have not decreased in the past 70 years. However, between the 1990s and 2000s, western governments were reassessed and more tasks were privatized (England & Ward, 2007; Pollit & van Thiel, 2007). Governments expected that private contractors would be able to innovate more, deliver quicker, reduce costs, and operate more efficient (Savas, 2000) resulting in integrated contract types. This research aims to provide insight into the relationship between the contract type and the management of cost groups, in Dutch national infrastructure projects in order to improve cost management. To provide an answer to the main research question, a literature study has been performed followed by a statistical analysis of 68 infrastructure projects with contract types including, RAW (n=24), E&C (n=22), and D&B(M) (n=22). Combined with the expectations of the expert panel this study concludes that there is no relation between the contract types RAW, E&C, and D&B(M) and the cost management of Dutch national infrastructure projects. However, it has been observed that project members of a contractor overestimate the relationship that D&B(M) projects should have higher cost overruns. This study concludes that the cost performance, of cost groups other than engineering, differ insignificantly and marginally small between contract types with varying design responsibilities. Moreover, the expert panel assumes that more information leads to less uncertainty and risks resulting in less cost overruns. Which is a common reasoning as stated in the GWW market analysis performed by McKinsey. However, this study concludes that the unavailability of information depending on the moment of contracting does not have an influence on the uncertainty of the cost performance nor the cost performance itself. Therefore, this study does not believe that the “two-phase-process” as proposed by McKinsey will contribute to less uncertainty about the cost performance. Instead, this study illustrates that Dura Vermeer confidently applies percentages to estimate relatively small, often process-related indirect cost groups which on average incur a cost overrun. Therefore, both the client and contractor should improve the process of constructing large complex infrastructure projects in order to improve the cost performance.