The Construction Industry holds an important role by contributing around 6% to the Gross Domestic Product (GDP) based on data from Market Prospects. Despite this substantial contribution, numerous projects within the industry struggle to attain their objectives effectively. Project uniqueness, coupled with the impact of project complexity, leads to difficulties in project identification and inaccurate selection of control methods. Thus, appropriate project identification, control method selection, and monitoring techniques are vital to anticipating such issues. Earned Value Management (EVM) emerges as an advanced monitoring method to anticipate the issues that include scope, time, and budget as controlled variables within a project. However, there remains a research gap in how to effectively apply EVM to diverse project types to effectively monitor the project. Through this gap, therefore a research question emerges:
“How to adapt Earned Value Management to various levels of projects based on the project complexity?”
To answer this question, the study will first outline significant aspects within EVM and assess the maturity level of organizations implementing EVM. Van Oord is chosen as the study location to gather data on their EVM application. The study then delves into potential adaptations of EVM and its effective application across diverse project types.
The research yields several significant outcomes. Firstly, the core EVM aspects are grouped under Earned Value Analysis, encompassing Planned Value (scope, budget, schedule), Actual Cost, and Earned Value. Project variance analysis, forecast calculations, and corrective action analysis are also recognized as critical components of EVM. The next step is understanding the organization maturity level, where this study reveals that EVM partially implemented in the organization and only in selected projects, following the threshold of EVM Maturity Level standards.
The next step involves the formulation of frameworks. The ABCD EVM Framework is developed based on the modified EVM 10-step model, focusing on elements such as Earned Value Analysis and the ANSI/EIA-748 standard as modified EVM components. One impactful aspect, as per the ANSI/EIA-748 Standard, involves determining the Work Breakdown Structure level, influencing the level of detail in schedule planning, budgeting, and progress tracking. Additionally, other variations include frequency of variance calculation and project forecast estimation. Various other aspects such as changes, responsibilities, reporting, and organizational decisions outlined in the discussion chapter are also differ on each project levels.
Moreover, the EVM framework is generated through TOE complexity analysis. Out of the 47 TOE Elements, 29 elements are being identified as influencing elements for the implementation of Earned Value Management. By adhering to the scalability factor from the ANSI/EIA-748 Standard and considering interview outcomes, several suggestions are formulated for Earned Value Management activities. The objective is to anticipate the high-scoring TOE elements for each project. The EVM aspects influencing this framework mainly concern the Project Measurement Baseline Plan, Budget and Schedule Authorization, the level of detail in the Work Breakdown Structure, and the recording of allocation and management reports.
Conclusively, variation in the adaptability of Earned Value Management are shown in the resulted frameworks for variety of project levels, as well as becoming tools to improve the organization maturity level. For practical application, this study recommends organization to implement EVM using the ABCD project classification or similar project sizing measurement approach while integrating insights from the TOE EVM Framework. This holistic strategy can enhance project monitoring and control across various complexity levels, contributing to the successful and effective outcomes of projects in the construction industry.

To prevent and reverse detrimental climate and biodiversity change, it is essential to motivate the housing construction supply chain to reduce the emission of carbon and nitrogen. The need to reduce the amount of emitted greenhouse gases and nitrogen oxides (NOx) is even more urgent in the Dutch housing construction. Currently, little research has been conducted into what hinders and motivates actors in the housing construction industry in their collaborative pursuit towards sustainable supply chain management (SSCM) in the Dutch housing construction industry.

The goal of this study is to provide new insights for actors in the housing construction chain, the government and science. To gain these new insights, the following research question has been formulated: How can the collaboration between actors in the Dutch housing construction industry be improved in the pursuit of sustainable supply chain management? This research was conducted through an in-depth case study research, based on literature research and semi-structured interviews with representatives from the most influential actor types in the Dutch housing construction supply chain. The housing construction supply chain contains a wide variety of actors with key players herein being main contractors, property developers and so-called first tier subcontractors

During the analysis of the interview results, an extensive amount of barriers and drivers were uncovered that actors encounter during the implementation of SSCM in the Dutch housing construction industry. For both barriers and drivers, it was found that subcontractors and property developers focus on the market and networking category, indicating they look more at the supply chain compared to main contractors. For main contractors, it seems they focus more on regulations, institutional barriers and drivers from within their own organization.

Based on the identified barriers and drivers, the following practical recommendations can accelerate the transition to SSCM in the Dutch housing construction industry. First, share knowledge with all actors in the supply chain. Second, develop a sustainable corporate culture that is reinforced both top-down and bottom-up in the organization. Third, some investments in sustainable operations are too high for a single actor to realize. Therefore, it is recommended that supply chain actors find effective ways to share financial burdens with each other in housing projects. Fourth and last, governmental institutions draft long term visions for the environment and subsequently translate this into policy.

The research findings can be used to inform and motivate main contractors, subcontractors, property developers and governments about practical implications and the use of policy instruments to achieve a sustainable supply chain in the Dutch housing construction industry. The combination of more intrinsic motivation from all actors in the housing construction chain can pave the way for creating a sustainable way of constructing houses.

This study addresses the critical need for specialized risk identification practices in green retrofit projects within the construction industry, particularly under the increasing pressure to meet the EU's net-zero emissions target by 2050. Focusing on the Netherlands, it investigates how companies navigate the unique challenges posed by updating existing infrastructure to be more sustainable and energy-efficient. Through a mixed-method approach comprising a literature review, field study in Voorburg, and semi-structured interviews with experts, the research identifies distinct risks such as performance risks, supply chain disruptions, and uncertainties in returns on investment. Royal Haskoning DHV's approach, including their Fast-Lane Method, is examined for its effectiveness in predicting energy use but noted for its limitations in estimating carbon emissions and broader retrofit tasks.

The study advocates for an integrated approach utilizing Building Information Modelling (BIM) to enhance risk management and project outcomes. It highlights the gap in current risk management practices that fail to fully address sustainability challenges in retrofits and suggests future research directions, including broader studies involving multiple companies and technologies, to develop more comprehensive risk management strategies for green retrofit projects.

One of the fundamental goals for the success of a construction project is found to be completion within the budget. To reach this goal, cost estimation is a key process which can be divided into the estimation of direct and indirect costs. Unlike direct costs, indirect costs are not directly connected with the performance of any particular element of a project which makes proper allocation of these costs a challenging issue. Although the classification in the ABK model (2018) provides clarity regarding the content of the indirect cost items, estimation of these costs (ABK) and especially the tasks for quantity take-off (QTO) were identified as time-consuming and lacking standardised guidelines and procedures.
At the same time, Building Information Models (BIM), which are increasingly used, offer an effective platform for linking data regarding construction costs. The fifth dimension of BIM in particular adds cost information to the 3D construction model. Full interoperability between the various information models is still a goal that has not been reached yet within the construction sector. Recent studies have examined inefficiencies caused by inadequate interoperability, like manual re-entry of data and duplication of tasks.
This research aims to positively contribute to the efficiency of the indirect cost estimation process by developing a 5D computer-based tool. The development of the tool was based on literature review and interviews with practitioners. Features of BIM applications were used and linked to the outcome of the indirect cost estimate. The tool was able to reduce manual interventions and reduce task durations, which resulted in a positive contribution to the efficiency of the indirect cost estimation process. Main benefits of the tool were hereby the structured guidelines for quantity take-offs, a reduction in manual intervention and time for QTO tasks and implementation of project changes within the outcome of the ABK estimate.

Precast concrete appears to be promising in dealing with delays in housing construction, yet long lead times are apparent in this industry. Lead time refers to the time that elapses between placing and receiving an order. The construction company Janssen de Jong recognizes the problem of sub-components’ long lead times in precast concrete house-building. Sub-components are those products being integrated into the precast concrete components and they are supplied to the precasting concrete factory by various suppliers. The company seeks to optimize sub-components’ lead times, so as to increase its competitiveness. Accordingly, the current research focuses on identifying the sources of sub-components’ long lead times in precast house-building industry and optimizing them, in order to improve projects’ performance in terms of time and costs. The research draws on literature review, interviews, mathematical optimization modelling and case study.

Literature review and interviews with Janssen de Jong, a precasting concrete factory, a windows and frames supplier and an installation technology supplier revealed the large batch size of batch-and-queue manufacturing method, as the main quantifiable source of long manufacturing time, affecting significantly the delivery of sub-components and so, extending their lead time. Batch-and-queue utilizes the equipment to its maximum capacity, yet leads to stock creation at each production step. On the contrary, one-piece-flow manufacturing method (batch size of one), was indicated as a value-adding process worth to approach, yet not easily achievable, not so efficient and more expensive. One-piece-flow refers to moving the product step-by-step through each process step without non-value-added time. The conflicting interests of the suppliers and Janssen de Jong call for solutions that could satisfy both time- and cost-related interests.

The mathematical optimization model was built based on the identified conflicting relation between reducing costs and shortening lead times, in relation to the batch size. This was done considering the arguments in favor of and against both manufacturing methods. In this way, the bias is reduced. Weights are assigned to each of the objectives, denoting their relative importance to the client. A set of optimal lead times and costs is obtained, after running the model for each supplier separately, enabling Janssen de Jong to improve the project performance as per the priorities each time.

A project of 23 precast concrete houses was utilized as a case study for the model validation. Out of the involved suppliers, only the windows and frames supplier made some data accessible. This supplier already follows one-piece-flow. Access to financial data was restricted, so, a supplementary Greek company, which is active in the same field and it is highly representative of the case, was utilized. The developed model yields reasonable results compared to the real figures.

Concluding, the model proves to be effective in optimizing sub-components’ lead time in precast concrete house-building industry. However, it is recommended the model to be validated using companies from other fields (e.g. installation technology company) and incorporate further information in a future version –complex to include this in the current thesis– to achieve even higher levels of realism and applicability.

The Paris Agreement was created in an effort to enhance the global response to the issue of climate change. To reach this goal, greenhouse gas emissions must be at least 40% below 1990 levels by 2030 and the temperature rise must be kept below 2 degrees Celsius this century. Moreover, the recent fossil fuel price increases, are pressing eye-openers to the geopolitical dependency on a small number of nations and mark the urgency of the energy transition.

Hydrogen generation as a means of energy distribution and storage is argued to be a viable solution to this challenge because this flexible energy carrier can be produced by any energy source and can be converted into various energy forms. The energy carrier is believed to be critical for decarbonising heavy industries, heating, and transportation.

Although hydrogen can be produced from a variety of energy sources, the only long-term key to facilitating the energy transition and establishing a new green economy would be through the electrolysis of water, fueled by renewable energy. To be economically viable, the energy would have to be provided at a large scale and at a competitive price. This makes it a global endeavour, requiring cross-border collaboration to create international supply chains.

With its potential to generate an abundance of wind energy, geothermal energy, and hydropower, Iceland is exploring its opportunity to produce hydrogen for its domestic markets and export markets. Therefore, this research is taking the Icelandic situation as a case study.

A lack of infrastructure to create, store, and transport hydrogen in significant amounts is one of the obstacles to developing the hydrogen economy. Infrastructure development needs effective coordination and substantial expenditures. In this sense, port authorities play a crucial role in bringing together all the relevant parties in the supply chain. However, creating a long-term plan to convince investors and other decision-makers presents a hurdle. The creation of a port master plan is constrained by numerous uncertainties, limited technological knowledge, and unknown social needs. There is a need for strategically roadmapping the port development process and thus structuring the decision-making process. So far, no hydrogen industrial port complex has been built and no studies have been performed about systematic thinking for the purpose of generating the possible pathways to develop such a system.

Through a single-case and practice-oriented design research methods, this research performs a SWOT analysis to determine influencing factors in developing a hydrogen industrial port complex in Iceland. This leads to the creation of an eight-phase Integrated Hydrogen Port Development-framework to narrow the knowledge gap as described above. Ultimately, this research also describes a narrative that describes practical recommendations for the Fjarðabyggð port master plan.

Diversity in project teams is a notion that remains very broad and ill-defined, while literature indicates a mixture of positive and negative effects. The goal of this research is to better define diversity, its dimensions and effects, and the ways in which projects are affected by it. This investigation assists in the creation of a set of guidelines, which can be used to assess the current levels of diversity, and which also lead to suggestions that minimize the negative and maximize its positive influence. To accomplish this, the research question is formulated as follows: “How are projects affected by diversity in the project teams?” The design of the research is divided in three phases. Firstly, an extensive literature review revealed the dimensions that are considered and the effects that are generated. Secondly, the development of a questionnaire explored the view of diversity and its effects in practice. A statistical analysis discovered the statistically significant relationships and patterns. Finally, an evaluation process aimed to better explain the findings and provide some insights in how certain conditions are managed. The diversity dimensions’ matrix that was developed through the literature review assisted in the formation of the first, broad definition of diversity in literature. Through the statistical analysis, the number of dimensions was decreased by removing the ones that were considered either irrelative or not even present in the project teams. The investigation of the effects of diversity followed, along with their connection to the dimensions that mainly trigger them. As proved, effects are triggered by either the most present dimensions or by dimensions of special significance. Most of the effects recorded do have a positive influence on the atmosphere of the team and the performance of the project, by achieving for instance better team cohesion and coordination, cooperation, decision-making and creativity. As indicated in the findings, diversity should be further explored. The proposed guidelines can be used to recognize the levels of diversity in the project team and the effects that might be triggered. In this way, the ones that cause negative influence can be managed to boost the atmosphere of the project team and the project performance. The process followed could be repeated by applying some alterations that will assist in the deeper investigation of the variables. For example, the implementation of the guidelines in real projects would verify or reject the findings, leading to the creation of a more extensive guidelines or even a framework. Similar research can also be designed, by changing the way the effects are defined. Professionals could also start applying the guidelines, aiming to recognize the mechanism and control the triggered effects efficiently. Furthermore, the onboarding process followed by new employees and the team bonding are some aspects that should be handled carefully. Investing time and other resources related to these aspects should be among the priorities, since the influence on the team and project aspects is significant.

The goal of this research is to create a design for a method to enable the generation and implementation of evidence-based throughput times in the planning process of the construction industry. The current planning process and the generation and collection of throughput times relies heavily on experience-based information. Generating throughput times with data analysis could contribute to the creation of a more accurate and predictable project planning. The proposed method is necessary since the current planning process in the construction industry has a number of factors that obstruct a direct path to implementing data analysis. The current planning process is analyzed by a number of interviews with project planners and additional talks with a panel of experts in the planning process. A literature review is used to analyze how other industries use data analysis in their processes and what conditions are necessary to make data analysis possible in a planning process. Additional interviews are used to find the possibilities of data analysis in the planning process. A case study of one infrastructure construction project is used to find the missing aspects in the current planning process that would possibly enable data analysis. The case study is analyzed by following the steps of the Cross Industry Standard Procedure for Data Mining (CRISP-DM). The final product of this research is an alternative version of the CRISP-DM method. This method is focused on establishing a database filled with planning information, design information and combining those two datasets. It proposes steps to avoid undermining currently present intricate negotiation processes between contractor and subcontractor. The method makes sure the database is expanded and diversified and that proper evaluations steps are in place and that a benchmark is met in the accuracy of output values. The steps are divided in separate cycles to be applied on individual construction activities (e.g., sheet piles) since there is so little information available and it would not be feasible and justified to implement the steps on all construction activities. It is recommended that the proposed method is used to provide a proof of concept of generating detailed throughput times of construction activities in the planning process of the construction industry. This proof of concept is necessary to expand the data mining operation and try to fit evidence-based information in the workflow of project planners.

The Dutch public procurement market is a multi-billion industry, with a total value of 73 billion euros per year. Competitive tendering is the most popular method of selecting a supplier for the required construction services. The realisation of a tender bid is an expensive and complex process, established on the intersection of various disciplines e.g. safety, constructability, finance, cost estimation and risk management.

Machine Learning has been a popular method in various industries to predict future outcomes and uncover patterns in historical data but remains a rather novel phenomenon in the construction industry. Machine Learning models have been developed in the past to aid tender management, but not with a focus on predicting the contractor’s tender price.

The objective of this research is to develop a Machine Learning tool that is able to predict the tender price of infrastructure projects accurately and is able to assist the contractor’s tender professionals in their decision to tender.

In order to achieve this objective, the following research question was formulated:
How can a Machine Learning algorithm, predicting the tender’s price using tender project data, be developed to support the contractor’s decision to tender?

First, a literature study is conducted to explore the state-of-the-art developments of Machine Learning within construction tender management, discover what the most popular regression algorithms are and what the most important tender features are that influence the tender price. Based on the most important tender features and interviews with tender professionals of a Dutch contractor, an extensive list of 93 tender features is filtered until a final set of tender features remains. Data on these tender features are collected in order to be used as input for the Machine Learning model.

The SVR model performed the best with an R-Squared of 0.846, implying that 84.6% of the variance of the tender’s price could be explained by the model. The SVR model includes an optimised set of features, which is a subset of the initial dataset. The initial estimate is considered to be significantly more important than the other features.

In order to implement the Tender Price Predictor in the organization of a Dutch contractor, attention should be paid to the required effort of the users and to ensuring a high quality of tender data. Requiring too much effort from tender managers entering the input data into the database may result in worse quality of data. Both the users of the model and the managers submitting tender data should be trained accordingly in order to obtain maximum effectiveness.

It should be noted that some important features, according to practice and literature, are omitted from the final dataset. Although the final set of features complies with the requirements of generic features and sufficient occurrences in either literature or the interviews, they were not present in the database of the contractor. These omitted features are: ‘Project team experience’ and ‘Location’

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.

The transition to a circular economy requires reducing waste and rework in construction projects. Thereby, the evaluation of building circularity in the early design phase is of great importance. However, due to the current design workflow, such practice is hindered because there is not enough information to evaluate building circularity in detail in the early design stages. An improved workflow to emphasize circularity more in the early design phase is thus needed. This research explores the current workflow and designs an improved work procedure with limited information available by incorporating an automated decision support tool to assess early design phase building circularity, aiming to improve the working efficiency and efficacy. This tool has been designed based on interviews and literature studies, and verified and validated with practitioners. This study serves as a starting point to rethink the workflow to improve circularity with current technological potentials.

Despite the severity and high frequency of cost overruns in construction projects, it is considered a rule rather than an exception. This phenomenon occurs when the initially estimated budget does not suffice the actual costs needed to realise the project. Uncertainty and bias challenge the ability to make cost estimates. Incorrect estimates of indirect costs, including risks, reservations and project organisational costs, are acknowledged as a frequent cause for cost overruns. Regardless of the risk and cost contingency management tools in literature and their application in practice, project uncertainties are still underestimated and insufficiently managed.

During the execution phase projects are monitored with performance indicators, which provide information about past events or activities. This means these indicators are lagging, hence it limits proactive project management. On the contrary, leading indicators could function as early warning signs as they present themselves before potential issues arise, or risks materialize.

The objective of this research is to improve the cost contingency process by implementing early warning signs, in order to proactively manage projects and minimise cost overruns and materialized risks. In order to achieve this objective the following main research question is formulated: “How can early warning signs be used in large construction projects to improve accuracy of cost contingency estimates and management in order to minimize cost overruns?”

Concluding from the empirical study, early warning signs can be implemented in the cost contingency process by shifting the focus of risk management from mitigating and managing the effects of risks towards the causes of risks. Subsequently, risk strategies and mitigation measures can be more effective when aimed at the origin of the issue, instead of the direct issue leading to the risk. It is valuable to examine the risks as a system or network, instead of single problems, because it provides a better representation of reality and the links between risks or other events reveal information about correlation or side effects. Consequently, mitigation measures can increase in efficiency, when one cause, leading to multiple risks, is targeted. Furthermore, materialization of a risk is detected as an early warning sign which contains information about causes or circumstances that trigger other risks as well. Additionally, the increase of a RISMAN score indicates a change in project circumstances and therefore can be used as an early warning for materialization of risks. The justification for an increase in RISMAN score is diverse, and should thus be analysed to reveal the specific information needed to prevent materialization of risks.

A common database contributes to the early warning sign approach as well, because it overcomes the in the case study identified ‘surveillance filter’, by improving collection and transfer of information. Tracking the cost contingency increases the accuracy of this estimate in general, because it provides insight into the development during project phases and the actual spending pattern. And when this info is stored in a database it allows referencing from previous projects, hence including an ‘outside view’.

It is a well-known fact that the construction industry operates under high levels of complexity and uncertainty, which gives rise to challenges such as ineffective communication, lack of trust, insufficient support from the higher management, etc. Collaboration has demonstrated to be a solution to all these problems. In order to stimulate collaboration, there are certain tools such as early involvement of all parties, co-location of all parties, team building activities, hiring a facilitator, etc. which are effective. This research revolves completely around these collaboration tools adopted predominantly in the design phase of infrastructure projects using integrated contract forms. The following contract forms have been studied: Bouwteam (Netherlands), Alliance (Finland) and NEC4 (United Kingdom). The collaboration tools used in these projects have been analyzed and compared, after which recommendations have been proposed to each contract form to enhance collaboration. The goal of this thesis is to stress on the fact that merely introducing the concept of collaboration in the contract does not guarantee the success of collaboration. This thesis calls for more attention to be paid to the recommended collaboration tools even before finalizing the contract form for a particular project.

One of the ways that Transmission System Operators (TSOs) can become more sustainable is by integrating sustainable goals in their projects using the associated procurement and tender processes. However, there are several limitations related to this integration. This research aims to identify these challenges by looking at the Dutch TSO, TenneT and its specific context. Furthermore, the research aims to provide a decision-support framework through which these limitations can be countered and the integration of sustainable goals in projects can be achieved.
First, a literature study was conducted to define sustainability and the concepts associated with it. To properly understand the context of TenneT and identify the limitations associated with sustainability, company professionals were interviewed. This pointed to the need for prioritisation and gradual integration of sustainability measures. A desktop study was also conducted to identify the company’s sustainable goals, their associated measures, and their real-life applications. A decision-support framework for integrating sustainable goals in projects, based on Multi-Criteria Decision-Analysis (MCDA) was proposed. Using the Best-Worst Method (BWM), as the selected MCDA method, developed by Rezaei (2015), a sustainability workshop was organised where decision-makers from TenneT were asked to select relevant sustainability goals for TenneT, and the ones selected by three or more decision-makers were then used for performing the BWM. To avoid focusing on already well-performing sustainability goals, the performance of their associated measures was studied, using a Maturity Model based on the work of Silvius and Schipper (2015). Finally, an Importance-Performance Analysis (Martilla and James 1977) was performed, to assess future actions for each sustainable goal. The BWM showed that the Planet aspect was selected as the most important one for stimulating sustainability in projects. Additionally, Reducing Emissions was selected as the most important sub-aspect while in the People aspect, Health and Safety ranked first. The Maturity Model showed that the least integrated goals in projects are Human Rights, Labour Conditions and Decent Work, Energy Consumption, Materials and Natural Resources and Circularity and Waste. The BWM and Maturity Model also produced interesting results regarding the awareness of decision-makers and how they perceive sustainable goals and the performance of their associated measures in projects.
Based on the Importance-Performance analysis, the research suggests integrating the sustainable goal of Circularity and Waste in the company’s following projects. This can be achieved by using existing sustainable measures, such as the Raw Material Passport (RMP), in the tender process. Using measures such as the RMP in the pre-qualification phases or selection phase, as entry requirements with specific targets to be met, or as an award criterion, aiming to create added value for the project, can stimulate the contractors and suppliers to act more sustainably. This will in turn increase TenneT’s sustainable performance and will help the company meet its own sustainable targets.

One way to reduce the environmental impact of the construction sector is the inclusion of environmental requirements in the procurement of construction projects, also called Green Public Procurement (GPP). This thesis first analysed the current inclusion of environmental requirements in the invitation to bid, bid and assessment of the bid. Hereafter, the results were evaluated and a proposal to develop the inclusion of environmental requirements has been made. A misalignment of environmental inclusion was found. Environmental requirements were included in 86% of the 70 invitations to bid, 74% of the bids and 46% of the assessments of the bid. Three defects possibly causing the misalignment were obtained. First of all, ineffective inclusion of environmental requirements in the invitation to bid. Secondly, missing feedback and scores in the assessment of the bid. Thirdly, when feedback was included on the environmental requirements, it was unclear or very limited. As a consequence, environmental requirements are not taken into account in the procurement process. Four purchasing experts from Dutch provinces have been interviewed to evaluate the three limitations and come up with opportunities to resolve them. By looking critically at the expert interview results and comparing them to the results of the content analysis, two problems were noticed. First of all, window dressing: ambitions to improve the inclusion of environmental requirements were stated, but not realised. Secondly, a lack of responsibility. The window dressing and lack of responsibility are caused by the absence of environmental management in the IPM-model. No one is taking action, because no one is responsible. It was concluded that a change in the IPM-model is needed to create responsibility and that the procurement process needs to be improved to incorporate environmental requirements more sufficient. It is recommended to the client to include environmental management in the IPM-model. The environmental management department should have four responsibilities: ensure environmental inclusion, correct limited or incorrect environmental inclusion, learn from mistakes made and develop environmental inclusion based on acquired knowledge. Secondly, a learning process needs to be started. It is recommended to both the client and the contractor to document feedback and review the environmental inclusion in the invitation to bid and bid. The feedback and reviews have to be interpreted and used to improve future invitations to bids and bids. By documenting past performances, future performances can be improved.

Building Information Modelling (BIM) constitutes an innovative way of creating and managing data among multiple disciplines and it is recently introduced in Architecture Engineering and Construction (AEC) industry. The adoption rate of BIM is considered low due to a lack of awareness regarding these methodologies and their outcomes. Although many studies present the benefits of BIM, there is still insufficient knowledge regarding its monetary value and the way it can be embedded in a company. Researchers have not yet been able to accurately substantiate all of the benefits because their intangible nature makes their quantification challenging. Apart from the lack of exact quantification of the profits, the Threats of BIM cause the need for evaluation. The objective of this research is to evaluate the costs and benefits of BIM implementation. The quantification focuses on the Execution phase of a project when BIM costs are considered to be the highest. What could constitute a standard method of evaluating the costs and benefits of BIM in Construction Projects? The answer to the main question that motivated the research is given through the development of a transparent and evaluative Framework that is based on Cost and Benefit Analysis (CBA) and is potentially applicable in any construction project. This Framework is structured on an Excel Spreadsheet, analyses BIM results and produces numerical data. The purpose of this method is to capture information, quantify costs and benefits and calculate the benefit-to-cost ratio. Consequently, the Framework is applied on 5 construction projects, namely, the Case Studies, and generates the B/C ratio which ranges from 1 to 8. Briefly, the evaluative method considers as inputs the BIM costs and workflows, is applied on the construction site in order to capture information on time and quantify the costs and benefits. The result is the CBA of BIM implementation and particularly the B/C ratio. Once the Framework is implemented, users are able to evaluate BIM costs & benefits, update BIM strategies and thus, raise awareness within academia and industry.

The construction industry faces problems in interoperability. Information is not easily interpreted nor accessed by participants. The insufficient level of interoperability occurs due to fragmentation between disciplines in the construction industry. To enhance interoperability, Building Information Modeling (BIM) formed a collaborative model that connects team members. However, the different disciplines continue to share information that cannot be directly used by others. This situation is present between designers and cost engineers. Despite working in a 5D BIM model that considers cost information, fragmentation between these disciplines persisted. Costs do not guide the design and they are computed after the model matures. Furthermore, the detachment of design and cost estimation processes led to the segregation of information in BIM. Addressing the problem of fragmentation between processes, the research aims at investigating the main question: How can design and cost estimation be effectively integrated using 5D BIM?
To answer the research question, several steps were performed. From the case study research, the following issues on fragmentation and BIM application are identified: [1] unsteady involvement of the cost engineer in the design, [2] limited influence of the cost engineer on the design, [3] model complexity, [4] incompatibility of model information and cost estimation, [5] absence of standardized and uniform information representation, and [6] resistance of clients and practitioners to the application of BIM/5D BIM.
By countering these issues, the “Integrated Design – Cost Estimation 5D BIM Process” is designed to answer the research question. The integration between design and cost estimation via 5D BIM focuses on cost driving components which are components influencing costs. Accordingly, these components are considered as key for communication, discussions between designers and cost engineers, and model development. Focusing on cost driving components, the process balances the information in the model. The information in the model is checked for compatibility with the estimate’s accuracy. Furthermore, the process proposes the consideration of the cost engineer’s perspective in the design. Then, 5D BIM is incorporated in the designed process by standardizing information and following the semi-automated approach for cost computation.
To assess the effectiveness of the integration addressed in the research question, a pilot case is performed to test the process in a running project. From the observations, it is concluded that the process provided a standard representation of objects, enhanced the communication between the designer and cost engineer, and involved the cost engineer earlier in the design. Furthermore, the pilot case led to the conclusion on barriers to BIM implementation. These include: the cultural change from individual effort to collaboration, lack of support from the management and client, inadequate planning for BIM application, and the inexperience in applying 5D BIM. These factors limited the successful implementation to reach effective integration. Despite the limited integration achieved in the pilot case, project participants and interviewed BIM experts ensured that the process leads to effective integration. However, it is crucial to respond to the noted barriers to have effective integration between designers and cost engineers via 5D BIM.

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.

In this research, a practical process framework is developed to facilitate the transition to circular urban area development (CUAD) of the MerweVierhavens (M4H). One of the five objectives of the Rotterdam Makers Districts is to become the pilot for the circular economy in the built environment of Rotterdam. M4H is an old harbour area that belongs to the Rotterdam Makers District. In previous research done by Team 1010, the potential circular flows for M4H have been analysed. The result was an overview of what is necessary for the transition to the circular economy of the built environment. However, no further steps have been taken so far. The transition to CUAD is rather complex, and the current urban area development process does not fit most circular strategies. This research, therefore, examines the process strategy needed to facilitate the transition to CUAD. Moreover, previous research has shown that the transition to CUAD requires a practical tool or framework. That is why, in this research, a practical process framework that facilitates the transition to CUAD, called the CUAD framework, is developed. The CUAD framework is based on the conditions for the transition to CUAD distinguished through the literature study and two case studies. The CUAD framework is tested through a pilot study conducted with stakeholders involved in the development of M4H. The CUAD framework can be applied to facilitate the complex and dynamic environment by developing areas with a CUAD vision, through short cycles and by incorporating multidisciplinary perspectives. The pilot study has indicated that the CUAD framework can indeed facilitate aspects of complex CUAD projects. However, the framework should be further developed. Nevertheless, this research has shown that CUAD is an ongoing learning process.

Many infrastructure projects cope with a cost overrun and time delay due to the lack of effective design change management in case of design changes. To implement these design changes, an effective change process is necessary. This process guides the project team in identifying, documenting, evaluating and managing design change. With this technical tools are needed for implementation of change, namely BIM(Building Information Modelling). By using BIM, assessment is made on whether design changes are feasible and what consequences it may have on planning, costs, re-work, and clashes. However, current knowledge is lacking on how to use BIM when implementing a design change in a project. This research aims to set up a procedure that can be used by the project team for implementing design changes during the execution phase of infrastructural projects. To achieve this objective, the main research question is answered by analysing case studies. Hereby, both qualitative and quantitative analyses are carried out in three cases in the infrastructural field. Both analyses are subdivided into the organisational dimension(for the change process) and technical dimension(use of BIM). For the qualitative part, semi-structured interviews are held with contract managers and BIM managers. For the quantitative part, samples are taken to analyse each project. These samples consisted of all contractual changes in the project that led to a change in the design and which have been implemented after the execution phase has commenced. The results of the literature study and the case studies are used to develop a procedure to be used by the project team in case of design changes during the execution phase of infrastructural projects. By using this procedure, the project team gains a full understanding of how the design change process should proceed and which steps they have to take for effective implementation of design change with using BIM.