The COVID-19 pandemic has affected the construction industry in the Netherlands as projects came to a stop and project teams struggled to collaborate remotely. To cope with the effects of the COVID-19 pandemic and consequential virtual work environment, it is crucial to have effectively collaborating design teams. A renown contributor to team success in design teams is trust. Trust contributes to project success as it aligns the interest of stakeholders, increases the willingness to share information and improves team performance. In previous research it found that prior ties, or interactions in previous working relations could result in an improved level of trust in the design team. Moreover, expectations of future collaboration, or future ties, also improve the levels of trust in teams. These ties could therefore be used to increase the levels of trust and subsequently result in more efficient team processes. In addition, as the design team members were subjected to the restrictions related to the pandemic, it is important to investigate how this virtual work environment affects trust development. This research aims to fill this research gap and utilize its results in order to enable design team members to improve the levels of trust in their teams while coping with the effects of the change to a virtual work environment. By performing the research based on a literature review and a survey analysis, it is concluded that ties are an important factor in the development of trust. By utilizing the individual aspects of these ties, design team members can improve the levels of trust. It is suggested that prior ties are more important for trust development than future ties. However, it should be mentioned that prior ties are no silver bullet. Prior experiences may induce unmet pre-existing expectations and laxity. In addition, the potential non-beneficial effects of virtual meetings on trust in the design team should be considered. To deal with these effects it is advised to organize social and face-to-face meetings as these improve interpersonal connections. The research results indicate that this knowledge is not yet common and should therefore be emphasised. Lastly, it has to be mentioned that when considering this conclusion, it is important to recognize that certain limitations are present. Especially the considerable small sample size of the survey, which resulted in many other limitations like an unequal representation in personal and organizational roles, should be considered.

Sustainability is seen as one of the most important challenges faced by the world today (Silvius, 2017). Within EPC companies, there are quite some ambitions at the strategic level to integrate sustainability into project procurement, but implementation at the project level is still quite limited. Additionally, existing literature focusing on sustainable procurement or sustainability within supply chains (i.e., suppliers/(sub-)contractors), in the domain of EPC companies in the oil, gas and petrochemical industry is also quite limited. This research study thus aims to develop a strategy on how EPC companies in the Energy & Chemicals (E&C)/Process industry can integrate sustainability into their project procurement practices, thereby adding to academic literature and practice. To achieve this objective, this research study was conducted in three main phases. In phase one, a thorough literature and document review was conducted, resulting in a conceptual sustainability framework that could be integrated into an EPC company’s project procurement practices such as prequalification and supplier/(sub-)contractor selection. The sustainability framework consisted of a set of sustainability criteria and performance indicators which can be used to assess the sustainability level of an EPC company’s suppliers/(sub-)contractors. In the second phase, semi structured interviews were conducted to understand views from practice regarding the topic of sustainable procurement. Main insights gathered included understanding the enablers and barriers encountered by EPC companies during implementation of sustainability into procurement, the prioritization of the identified performance indicators, incentives to stimulate sustainable procurement and suggestions for improvement. The third and final phase synthesized all the findings gathered so far, to propose a strategy or solution for EPC companies to integrate sustainability into their project procurement practices. This research study concluded by providing a holistic set of recommendations to all actors involved in executing a project, such as clients, EPC companies and supply chain actors on how sustainability can be effectively and efficiently integrated into project procurement practices.

Programmes in the Dutch infrastructure sector can contribute to overcoming the industry’s lagging performance and the increasing amount of renovation of work it is currently facing. Additionally, they have the potential to integrate the fragmented supply chain while facilitating better coordination of the projects being executed more effectively and efficiently. However, they also introduce chaos to the collaboration that can be detrimental effect on the programme’s outcome. Although there is extensive literature on inter-organizational collaboration in projects, little attention has been paid to the programme context. It is still unknown how governance should be organized to facilitate inter-organisational collaboration in programmes Therefore, this study responds to the call for research. Two Dutch infrastructure programmes were studied to understand the governance approach used and how it facilitated inter-organizational collaboration. The results from the case studies showed that inter-organizational collaboration in the early phases of infrastructure programmes is facilitated by an interplay of relational and contractual mechanisms corresponding to the six dimensions of governance: goal-setting, capability building, rewarding, roles & decision-making, coordination and monitoring. This governance mechanisms are established by the programme level and the contracting authorities’. They intend to provide a framework for organizational processes, decision-making, and coordination in the programme, while integrating the different levels of the programme. Additionally, this research provides a model that aims to provide a structural way to organize future programme governance while allowing public clients to analyze their choices better

In recent years, the concept of sustainability has grown in popularity and has become a critical strategic component for businesses (Garza, 2013). Corporate organizations, as the industry's productive drivers, play a crucial role in attaining sustainable development. Thus, the problems have shifted from "WHY" to "HOW" to integrate sustainability into management decisions at all organizational levels (Epstein & Buhovac, 2014). Corporate entities, such as EPC contractors, tend to realize their strategic goals and produce value for their shareholders through projects. However, for sustainability to be evident in all organizational practices, these methods must be well adapted at the operational level. Organizations are increasingly struggling to translate their strategic goals into project-specific activities (Marcelino-Sádaba et al., 2015; Engert & Baumgartner, 2015). In practice, there is a significant gap between strategy formulation and project implementation (Økland, 2015). The problem addressed by this study is the gap between the formulation of strategic level objectives and its implementation at the operational level. According to researchers, integrated ways to putting sustainability into action are inadequate, and there is no systematic approach to effectively incorporating sustainability into projects (Silvius et al., 2012; Sabini et al., 2019; Epstein & Buhovac, 2014). As a result, sustainability goals often remain confined at the strategic level.

The purpose of this research is to provide solutions to the EPC contractor to overcome the barriers to enhance the integration of sustainability in projects and bridge the implementation gap. The results will provide a structured approach in connecting high-level sustainability objectives to more concrete and tangible solutions for the project. This research is an attempt to respond to the lack of empirical studies on the implementation of organizational sustainability strategies and helps reveals how organizations can move towards translating strategy into action and overcome the barriers to sustainability implementation.

To achieve this objective, the research is divided into three main phases. In phase one, literature review and document review was conducted. Through literature review five elements essential for implementing sustainability strategies were identified i.e., organizational decision-making, lifecycle thinking, balancing the triple bottom line, stakeholder engagement, and proactive approach. Through document review the gap between strategic and operational level was highlighted. In the second phase, semi-structured interviews were conducted with people in the top management and project managers to identify the barriers to sustainability implementation resulting in the gap between strategic and operational level. In total 20 barriers were identified. The interviews also included understanding the application of elements identified from literature review in practice. The third and the final phase, synthesised all the findings from phase one and two, and proposed solution to the EPC company to integrate sustainability in projects. This was done by providing mitigating actions to overcome the identified barriers and proposing a framework to translate strategy into action, thus bridging the implementation gap. Using the suggested framework to make the strategy explicit has the following benefits: it encourages communication and strategy execution, allows for strategy discussion within the organization, and tracks progress toward long-term goals to determine whether the strategy is clear or needs improvement.

Currently, the infrastructure industry is in transformation and moving towards new project delivery approaches. Aiming to improve the predictability of projects and due to a growing desire for collaboration between clients and contractors, the two-phase model has made its entrance in the industry and has been gaining popularity.
During the first phase of the two-phase model, client and contractor work together on the design. The first phase results in a detailed design including the price for execution. After a successful first phase, client and contractor come to an agreement for the execution phase. The price determination of the execution costs is delayed until after the first phase. The contractor therefore has a better grasp of the project risks and is in a better position to offer a more reliable price. The two-phase model is relatively new on the market and therefore has not yet been standardized. The elements of a two-phase model have not been identified scientifically. This research contributes to making reasoned choices on how the elements of a two-phase model can be operationalized in infrastructure projects in a way that the two-phase model contributes to achieving the project's objectives.
The main research question of this study is: What is the optimal operationalization of elements in designing the first phase of the two-phase model in infrastructure projects?

In the past decades, sustainability has become increasingly important for the construction industry, in particular highway infrastructure, as it can generate both positive and negative impacts on the social and physical environment. As a result of the impact on the environment and the growing awareness of environmental protection, the effects on society and economic development, there is a pressing need and sense of urgency for the sector to become more sustainable. For a highway to be truly sustainable it needs to take the social, environmental and economic dimensions of sustainability (People, Planet, Prosperity) into account. Over the past decades, some sustainability assessment (SA) approaches have been developed in an attempt to integrate sustainability in the assessment of infrastructure projects. Despite these attempts, these SA approaches do not address all the dimensions of sustainability thoroughly and are biased to either an environmental or an economic assessment, while the social dimension is taken less into consideration. However, how designers and decision-makers can integrate these dimensions into the assessments of highway design options is less known. This lack of integration of the three dimensions of sustainability makes it impossible to evaluate and assess the sustainability consequences of highway design choices and options and thus represents a significant limitation.

To address the observed problem, the main objective of this research is to not only provide designers and decision-makers with a SA tool that integrates all three dimensions of sustainability, but also with an understanding of how this can be used.

The triple bottom line (TBL) theory coined by John Elkington, a well-known concept in sustainable development (SD) was selected as a sound theory regarding the three interdependent dimensions of sustainability. A total of 64 SA criteria from the construction and infrastructure sector were identified through surveying recent literature, which formed the preliminary list of SA criteria. This was followed by a filtering process on the SA criteria and subsequently a questionnaire survey to establish which are relevant to the Dutch highway context. This resulted in the conceptual SA framework which consists of 36 SA criteria categorised in their corresponding dimensions of sustainability and related 9 themes. Next, the assessment procedure was provided for the conceptual SA framework, to form the proposed SA tool. In this tool, the best-worst method (BWM) is used to determine the weighting factors of the themes depending on the project. The tool was tested by applying it to a reference case (a highway project in the Netherlands). Based on the results from the reference case, the applicability of the tool was evaluated by an expert involved in the project. In the developed SA tool, the three dimensions of sustainability are integrated into one comprehensive framework specific for the Dutch highway context.

The conceptual SA framework provides a systematic overview of all possible aspects of sustainability that can be taken into account during the planning- and design phase of a highway project. In addition, it can help designers and decision-makers understand how the dimensions of sustainability can be used to decrease the negative impacts of highway projects and embrace the principles of sustainability with respect to environmental protection, economic profitability and human well-being, to make their highway designs more sustainable and to contribute towards SD.

The proposed SA tool can assess, compare, evaluate and rank design options based on the SA criteria. The SA criteria assess to what extent a design choice and option contributes to the creation of sustainable added value. In this tool, design options can be explicitly weighed upon all dimensions of sustainability, related themes and corresponding SA criteria which can support the decision-making.

Interface management (IM) is an emerging construction management practice that is mainly concerned with the integration effort of (mega)projects through the management of project interfaces. Even though a plethora of benefits is attributed to IM, a clear overview of how to effectively manage interfaces is non-existent. Without a general understanding on what IM entails, false expectations about its use are created. At the same time, IM developments from academic research are facing obstacles in their adoption in practice, for practitioners are often not represented in these developments.

The absence of situated knowledge (i.e. knowledge found and created in practice) in IM development is problematic, for a profession, or professionalism in general, builds on a body of knowledge comprised of integrated knowledge from theory and practice. For this reason, this research has attempted to take a step in the professionalisation of IM by converging the knowledge from theory and practice. That is, enriching the professional content by creating uniformity on the concept of IM and its key principles. The following research question underpinned this effort: What step can be taken in the professionalisation of IM, based on the perspectives from theory and practice?

For this, the theoretical perspectives on IM and its professionalisation were studied first, by means of a literature review. Then, practitioner perspectives were studied on the same topics through semi-structured interviews with twelve practitioners involved in the different domains of integral project management. These practitioners were all employed by a large Dutch engineering and consultancy firm. The gathered data was then subject to thematic analysis.

A comparison of the findings revealed a similar dichotomy in IM in both theory and practice: a distinction between the technical and organisational aspect. As the results showed possibilities for professionalisation from both sides, it was argued that professionalisation should ultimately happen on both fronts.

To create a basis for professionalism, an appropriate means to integrate the theoretical and situated knowledge needed to be found. To this end, literature on the professionalisation of related construction management disciplines was consulted. Inspired by the professionalisation of risk management, a set of key principles was deemed an appropriate medium to integrate the theoretical and situated knowledge of IM. Hence, a rough guide to IM has been created containing key principles. These principles have been validated by two IM experts in separate validation interviews.

Concluding, the development of a set of key principles of IM is the answer to the research question, which in itself provides a step towards professionalisation. Uniformity on the topic has now been created by the convergence of knowledge from theory and practice. The principles thereby lay a foundation for (professionalism in) conducting IM, while leaving room for customisation at the same time. Practitioners from the different roles of integrated project management are recommended to use the principles at the start of (infrastructure) construction projects to create an understanding of interfaces and IM in general. It is believed that in this way the established uniformity on paper can be translated to practice.

Cooperation figured prominently in the Dutch construction industry’s agenda over the past years. In 2016, major clients, sector organizations and the relevant market parties officially committed to promote a culture based on good cooperation and healthy relationships by signing the "Market Vision" (De Marktvisie, 2016). This document illustrates the objectives, principles and necessary changes to achieve this ambition in 2020. However, according to the report of Rijkswaterstaat (2019), there have not been structural changes in cooperation within the supply chain where fighting relationships, self-interest and opportunistic behaviours still prevail. The unattractive risk-return profile, i.e. the ratio between the expected return and the amount of risk undertaken by contractors, of large projects in the civil engineering sector is considered to be a barrier that prevent this change. The current approach to risk management is one factor that contribute to decrease the risk-return ratio. According to the report of Rijkswaterstaat (2019), market parties have the impression that risks are not always allocated to the "natural owner". The natural owner is the party that has the knowledge, ability and financial capacity to manage a certain risk. Market parties have more or less consciously accepted risks under competitive pressure although Rijkswaterstaat argue that during the tendering process of large complex projects some risks are taken back based on the contractors’ argumentation. However, construction companies point out that the dialogue focus on limiting risks on the client’s side and they are not yet sufficiently stimulated to discuss their own risks. This research proposes risk sharing to fills the gaps of the current approach with the purpose of stimulating the development of cooperation. The scope of the research is limited to Dutch infrastructure projects procured by public authorities through Public-Private Partnership. The research objective is to provide partner organizations with a framework to share risk at the project level in order to foster commitment and cooperation for the long duration of the partnership. The first step to achieve the research objective is to investigate current risk sharing from a theoretical and practical perspective. This is achieved through literature review, exploratory interviews with employees of WitteveenBos and document review. The results of these activities are compared with the elements mentioned in the literature to stimulate cooperation. Afterward, a conceptual model is elaborated based on the
results of literature review and exploratory interviews. The purpose of the proposed conceptual model is to illustrate contractual and relational elements that can be added to the current risk sharing in order to promote cooperation. Then, the proposed risk sharing mechanisms that constitute the conceptual model are discussed with practitioners. This activity aims to refine the proposed risk sharing mechanisms in order to obtain detailed measures that form the risk sharing framework. Finally, the proposed framework is validated with experts in order to assess whether it meets the economic and functional requirements of its intended users and fits within the restrictions imposed by the current practice. The risk sharing mechanisms applied in the construction sector mentioned in the literature refer to financial incentives such as government guarantees, target cost contracts, etc. However, the literature study suggests that the attitude and willingness of partners to engage in cooperative behaviours is stimulated more by trust and relational norms than formal enforceable rules. Therefore, it can be argued that risk sharing requires additional elements in order to promote cooperation. The proposed risk sharing framework requires certain personal attitudes of team members in order to be effective in promoting cooperation. According to practitioners, partners should: • seek the participation of all team(s)members, internal and external; • take the initiative to help rather than being passive; • show behaviours oriented toward the achievement of common goals and mutual benefits; • be open and receptive to new ideas, different perspectives, external influence; Furthermore, an essential attitude is to accept and embrace the idea that risk ownership does not exclude the chance of managing a risk together. The legal boundary of having one risk owner should not prevent partners from being forthcoming and providing support to control risks. Based on the results of the discussion with practitioners, the proposed risk sharing framework is effective in stimulating cooperation only if partners coordinate with each other and commit to implement these measures together.

Today’s project complexity is constantly increasing leading to multidisciplinary project teams. Building a truly integrated team in projects where a partnership is necessary in order to achieve the desired outcome isn’t a one-off process that can occur automatically. It’s a procedure that has to be built up over a certain period of time (mostly during the front-end development phase) under a collaboration that will utilize in the best way the benefits of this one-team approach. In international projects cultural differences between the different teams is an important aspect that adds an additional challenge in reaching a successful outcome. It is therefore the project manager’s responsibility to create a team of engaged and committed people that have an aligned project goal and act as a whole and not as a set of wholes. Getting from cooperation to collaboration requires the presence of both a strong project leader and a competent project team.

This study explores towards the positive side of project uncertainties i.e., opportunity. Opportunities occuring in such projects has the potential to enhance the project’s initial objective and could add more value to the project. However, due to lack of an effective approach for opportunity identification and several constraints prevailing in such large projects, opportunities are not being identified properly. This study investigates the concept of opportunity in infrastructure projects and crucial factors that could stimulate opportunity identification in such projects along with constraint’s study that hinders such identification process. Here, a roadmap is developed for opportunity identification consisting of a procedure for identifying opportunity during tender phase with an assessment model that could help in identifying value-creating opportunities for the project. This identified opportunities could be then used by the project team to exploit benefit for the contractor involved in execution but also to the client for whom the project will be delivered.

Already back in 1970s, the Club of Rome concluded that the world would become unliveable for future generations, if population growth and industrialization keep up the same speed (Silvius, Schipper, & Planko, 2012). Despite this, today’s industrialization can not only be observed on land, but also increasingly in the marine environment. The “industrialization of the ocean” accelerates as sectors like offshore wind, deep water oil and gas as well as seabed mining emerge (Kronfeld-Goharani, 2018; OECD, 2016, p. 18). Therefore, more sustainable practices are needed (GPM, 2015; Hahn, Pinkse, Preuss, & Figge, 2015; Ugwu & Haupt, 2007) and the dredging industry is transforming. Next to minimizing impact, the value adding function of marine infrastructure is increasingly recognized. As the ‘productive driver[s]’ of the industry, corporate organizations, like contractors, pertain a key role to achieve such sustainable development (Hahn, Pinkse, Preuss, & Figge, 2015). Moreover, their innovative power provides the opportunity to bring about change in the industry and to leverage long-lasting competitive advantage (Kramer & Porter, 2011; Zhang, Oo, & Lim, 2018). Accordingly, to distinguish themselves during tendering and to thrive for profit maximization, conducting sustainable business becomes more and more important for contractors (R. Peenstra & Silvius, 2017, Tan et al., 2015). Responsible operations are no longer up for discussion, but are becoming central to value creation (Epstein, 2018). This results in corporate sustainability strategies (Peenstra & Silvius, 2017). The problem addressed by this study is the gap between strategy making and integration of sustainability on project level for contracting organizations. At present integrated approaches for sustainability implementation into practice are lacking (Epstein, 2018) and there is no systemic approach, how sustainability can be successfully integrated into projects (Sabini et al., 2019). Although most papers, studying sustainability in projects, provide managerial implications, their highly contextual conclusions can hardly be applied to other projects (Sabini et al., 2019). Therefore, sustainability integration remains fragmented and strongly correlates with the assigned project manager in charge of the project (van Walt Meijer, 2018; Wolfgang, 2017). Based on case study research, the study provides a success factor model entailing seven critical factors for success for pro-actively integrating sustainability into projects of marine contractors. For Science, this study unravels critical strains in managerial decision-making for sustainability on project level, which thus contributes to the scientific discussion thereof. For practice, the findings have the potential to go beyond highly contextual implications, though being derived from marine infrastructure context. This is because the seven critical success factors may provide guidance to other contracting organizations regarding the variables to consider to implement sustainability strategies on operational level. For science and practice, the conceptual C7 implementation approach tackles the need of an integrated systemic approach, which was claimed to be missing. It helps contractors to apply the (sub) success factors of the model in practice. The development areas (not, -or inconsistently fulfilled factors) can be derived and subsequently actions can be taken to close the gaps.

In practice, scope management is hampered by several bottlenecks. In this thesis, these bottlenecks are identified and solutions to overcome them are presented in the form of a scope management implementation guide. This guide provides insight in the steps that must be followed, the responsible actor of each step and the bottlenecks that hamper each scope management step.

Sustainability is becoming an increasingly important aspect of the infrastructure industry, however, incorporating it has proven to be troublesome. As such, this thesis focussed on identifying success factors that influence the implementation process of sustainability from idea up to and including the tendering phase for public infrastructure projects.

Sustainability within Project Management practice is a new and challenging territory. The current project management practice within the construction industry, particularly highway construction has not yet fully embraced sustainability. Recent literature shows a relation between project success and sustainability. Project success comprises of project success criteria and project success factors. A sustainability success sub-criteria framework of a highway is developed to identify critical success factors for a sustainability oriented highway project during the exploration and planning phase. Three highway projects and four respondents from each case are selected for cross-case methodology. Based on cross-case analysis, critical success factors are identified and applied in an Integrated Project Management model to improve chances of project success during the exploration and planning of a sustainability oriented highway project.