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J.M. Vleugel

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Master thesis (2026) - S. Brons, J.M. Vleugel, A. Napoleone
Fast-moving consumer goods (FMCG) firms compete through innovation, but the portfolios that result grow faster than they are pruned.

The literature on SKU rationalisation is extensive, yet it consistently presupposes that the data required to evaluate a delisting candidate is available in analysable form. This paper reports a design science case study in the European personal care division of a large multinational FMCG manufacturer, where that assumption does not hold. The division already received periodic, criteria-based delisting recommendations from a central analytics team, but could not readily act on them: the recommendations contain only a code and its financial figures, and the evidence needed to interpret them was dispersed across more than ten independently maintained brand files and successive, unconnected snapshots of the commercial reporting system.

A decision-support framework was designed, built, and evaluated in response. Two automated pipelines consolidate the fragmented sources, one of which recovers a multi-period view by stacking snapshots that individually contain none, and four dashboards present the resulting evidence for portfolio exploration and for the evaluation of individual candidates. Applied to three recommended products, the framework confirmed two for delisting and surfaced the strategic grounds on which a third, financially indistinguishable, was retained.

The confirmed delistings raise the gross margin of the brands concerned by and percentage points and remove stock-keeping units across country-market combinations, at a cost of € million turnover. The artefacts are in use within the division. The central finding is that the binding constraint on data-driven rationalisation was not the sophistication of the analysis, which already existed, but the accessibility of the evidence required to act on it. ...

A stated choice experiment exploring how out-of-home locations influence return decisions in the Dutch deposit return system

Master thesis (2026) - N.B. Leppink, J.M. Vleugel, M. Kroesen
With growing regulatory pressure to accelerate the transition to a circular economy, waste collection and return systems are becoming increasingly important. Their performance ultimately depends on user participation, since users determine whether materials are returned and re-enter the system. However, a gap remains between behavioural research and infrastructure design, as collection system planning often relies on simplified assumptions. Using the Dutch deposit return system as a case, this study examines how context influences return behaviour and how insights can support infrastructure design. A context-dependent stated choice experiment was conducted among 370 respondents. Respondents evaluated return and disposal options across airports and amusement parks, varying in walking distance and knowledge of return locations. A Multinomial Logit model and a Latent Class Choice Model were used to estimate the effects of these factors on return behaviour and to identify heterogeneity in these influences. The results show that return behaviour is strongly influenced by perceived effort. Walking distance significantly reduces the likelihood of returning containers, while knowledge of return locations increases return rates and partly compensates for additional distance. Although some contextual differences were observed, the preference to minimise effort remained largely consistent across contexts. A return-oriented class and a convenience-oriented class were identified. While positive attitudes and intentions increased the likelihood of return behaviour, these motivations did not always translate into actual behaviour when effort increased. By translating the estimated results into choice probabilities and aggregating these into expected return rates, this study demonstrates how user behaviour can be incorporated into infrastructure evaluation and design. The findings contribute to bridging the gap between behavioural research and waste collection system design.

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An operator-centred study in heavy-duty road freight

Master thesis (2026) - J.M. Brouwer, J.A. Annema, J.M. Vleugel, Kees Verbogt, Niels Achterberg
Decarbonising heavy-duty road freight requires freight transport operators to invest in alternative drivetrains under rapidly changing technological, economic and policy conditions. Although existing research provides substantial insight into the techno-economic and system-level feasibility of hydrogen trucks, less is known about how operators evaluate hydrogen as an actual fleet investment. This study examines how freight transport operators assess hydrogen trucks in heavy-duty road freight. A qualitative research design combined literature and desk research with 24 semi-structured interviews, including 18 freight transport operators and six secondary stakeholders, followed by a descriptive questionnaire among all 18 operators. The operator sample covered small, medium-sized and large firms across a range of freight activities and levels of zero-emission engagement. The findings show that hydrogen is evaluated as a potential but currently conditional zero-emission option. Economic viability forms the dominant barrier, particularly because of high vehicle costs, high and uncertain hydrogen prices, low transport margins and limited customer willingness to pay. Battery-electric trucks are currently perceived as the more concrete zero-emission alternative, while hydrogen is mainly considered for operations where battery-electric deployment may face limitations related to distance, payload, charging time, grid capacity, utilisation or operational flexibility. Infrastructure, long-term policy confidence, firm capacity and uncertainty further shape investment decisions. Overall, hydrogen is evaluated as a relative and use-case-dependent investment option rather than as a mainstream zero-emission solution. ...

A Case Study of Stakeholder Coordination and Governance at KLM Cityhopper

Master thesis (2026) - E.J. Toet, J.A. Annema, J.M. Vleugel
Sustainable Aviation Fuel (SAF) is considered the most promising short- to medium-term solution for reducing aviation emissions, yet large-scale adoption remains limited. This study examines how governance structures influence SAF adoption in the European aviation sector, using KLM Cityhopper as a qualitative single-case study. The study is based on fifteen semi-structured interviews and a document analysis. The interview and document data were analyzed using an integrated framework combining collaborative governance, sustainability transitions theory, and multi-level governance. The findings show that SAF adoption is constrained by fragmented responsibilities, misaligned incentives, and investment uncertainty, which prevent coordinated collective action. Five governance gaps were identified: unregulated supplier pricing, policy instrument incoherence, national ambition without binding instruments, a principal-agent mismatch within the Air France-KLM Group, and the absence of a formal coordination platform. The study proposes a hybrid governance approach that better aligns responsibilities, risks, and incentives across public and private stakeholders. By conceptualizing limited SAF adoption as a governance deadlock, this research contributes to the literature on aviation decarbonization and highlights the role of governance in enabling coordinated action for aviation decarbonization. ...

Bridging ESG Frameworks and Capital Allocation in Superyacht Shipyards

Master thesis (2026) - M.D. de Boer, J.F.J. Pruyn, J.M. Vleugel, A. Napoleone, Charlotte van de Kerk
The gap between sustainability reporting and capital allocation in capital-intensive, project-based industries is commonly diagnosed as a measurement problem. This paper argues that, for yard-level investment decisions in custom superyacht shipbuilding, it is instead a decision-logic problem. Reporting standards produce backward-looking information for external accountability. Investment choice instead requires forward-looking deliberation under deep uncertainty about regulation, legitimacy, and client expectations. Existing valuation, indicator-based, and multi-criteria approaches each address part of this problem but none is sufficient alone. The paper develops a modular non-probabilistic framework with four components. A European Sustainability Reporting Standards-grounded indicator basis and a System Dynamics Representation handle indirect and feedback-mediated consequences. AHP-weighted Multi-Attribute Value Theory aggregates non-monetised value, and minimax regret across bounded scenarios supports cross-context comparison. Monte Carlo perturbation of elicited inputs tests framework robustness. The framework is applied to four investments at a custom superyacht shipyard, selected to span scale, impact pathway, and scenario sensitivity. The application demonstrates three results. First, baseline-attractive and robustness-attractive investments diverge. A large strategic investment wins under additive aggregation but carries the highest maximum regret, while a small governance investment minimises regret across scenarios. Second, the System Dynamics Representation surfaces legitimacy and governance pathways that direct expert assessment systematically overlooks. Third, sensitivity concentrates in the consequence layer rather than the valuation layer, locating productive disagreement in empirical rather than normative questions. The framework does not eliminate uncertainty. It disciplines deliberation by making assumptions, trade-offs, and points of disagreement explicit and contestable.
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Master thesis (2026) - R.A.C. Hoogeveen, J.M. Vleugel, J.A. Annema, J.M. Kooijman, Quirin de Flines
This thesis examines how the Dutch legislative and institutional framework determines the opportunities and limitations for non-pharmaceutical fulfilment providers in the B2C fulfilment of medicines. It explores the legal, organisational and market conditions that would allow a non-pharmaceutical company to offer an e-commerce fulfilment service that complies with Good Distribution Practice (GDP), with using PostNL Fulfilment as a case study. An exploratory mixed-methods research design is employed, combining literature and desk research on the Dutch pharmaceutical supply chain and legislative context, a stakeholder analysis, semi-structured interviews with pharmacists and other stakeholders, and the development of eight fulfilment scenarios. These scenarios are analysed using a framework of legal requirements and market-oriented design criteria. An actor-level implication analysis then assesses the institutional and administrative consequences.

The results show that pharmaceutical logistics in the Netherlands are regulated by a pharmacy-focused licensing system based on roles and locations, in which pharmacists remain responsible for dispensing medicines and ensuring patient safety. Non-pharmaceutical participation is therefore only possible through carefully regulated hybrid arrangements that ensure compliance with GDP, verifiable separation of responsibilities and robust contractual oversight. While none of the examined scenarios are explicitly on legal basis, the feasibility decreases as the executing party's role becomes more similar to that of a full logistics back office, comparable to the operational structure typically observed in conventional non-pharmaceutical fulfilment services. This is due to interpretative grey areas at the interface between dispensing and logistics, as well as the centralisation of multiple pharmacies and the associated distribution of roles and medication flows. Market feasibility is greatest in predictable segments with large volumes (e.g. repeat prescriptions), although it remains structurally constrained by the highly regulated nature of the pharmaceutical supply chain, which is characterised by a limited number of dominant actors who largely shape market access and operational conditions. In general, scalable implementation requires step-by-step expansion and clarification of regulations/legislation and governance designs that can be monitored and audited.
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A multi-criteria decision support framework for strategic fleet management

The maritime sector faces mounting pressure to decarbonise in alignment with global climate objectives and regional frameworks such as the EU Fit-for-55 package and the IMO net-zero targets. For fleet operators such as the Port of Rotterdam, which aims to reduce Scope 1 and 2 emissions by 90% in 2030 and sail emissions-free from 2035, this involves navigating complex trade-offs between sustainability, cost-efficiency, and operational readiness. This thesis investigates how the Port of Rotterdam can optimise its fleet renewal strategy to minimise total polluting emissions and transition costs while maintaining functional capacity.

To address this challenge, a hybrid decision-support framework was developed, combining multi -objective optimisation with multi-criteria decision analysis. The optimisation model produced Pareto optimal strategies, using the ε-constraint method, that balance lifecycle CO2 emissions, total cost of ownership, and local air pollution. Multi-criteria decision analysis, using TOPSIS, enabled inclusion of stakeholder preferences in the classification of different transition schedules under varying assumptions about fuel types, material choice, and production location. Scenario analyses were performed to assess the robustness of the combined framework against various economic outlooks and environmental choices, such as fuel type, hull material, and production location.

The results show that lifecycle emissions are largely shaped by design decisions such as material and energy source, whereas local pollutants are very sensitive to the replacement schedule. The total cost of ownership shows limited sensitivity to scheduling (1–2% variation), while battery production and dismantling emerge as the dominant drivers of greenhouse gas emissions and financial impact. The inclusion of CO2 emission depreciation significantly altered the schedules of optimal results, raising ethical and policy considerations. Certain vessel classes demonstrated robust scheduling behaviour, in various strategic choices and economic scenarios, identifying them as low regret alternatives. Other classes were more sensitive to changes in the strategic choices or stakeholder preferences.

The framework successfully supported trade-off navigation, revealing how rankings changed under varying stakeholder preferences and scenario assumptions. However, several simplifications remain. The decoupled class structure limited the ability to model shared infrastructure and battery packs. The cost structures did not reflect strategic procurement differences, and the lifecycle assessment focused solely on CO2-equivalent emissions, excluding other impact categories such as toxicity or resource depletion. These limitations suggest that future extensions should integrate infrastructure co-optimisation, procurement variation, and broader environmental metrics to fully capture the system-level implications
of fleet renewal.

This research contributes a replicable, stakeholder-aligned methodology for sustainable fleet transition planning. It provides the Port of Rotterdam with a transparent and data-driven tool to align its environmental commitments with long-term operational and financial viability, providing critical insights for fleet operators pursuing low-emission transitions. ...
Amid increasing pressure to decarbonize logistics operations, hybrid distribution strategies that combine direct plant shipments with conventional two-echelon networks are gaining attention in the fast-moving consumer goods (FMCG) sector. This thesis investigates the trade-offs between logistics costs and environmental performance in such hybrid distribution networks through a case study at Procter & Gamble (P&G). A novel flow-based adaptation of the two-echelon vehicle routing problem (2E-VRP) is developed and implemented within a multi-objective optimization framework. Applying scalarization and ε-constraint methods, the analysis shows that while direct shipments from plants can lower logistics costs, they do not necessarily improve environmental performance. When emissions are directly minimized, two-echelon flows are often preferred due to their higher vehicle utilization. Sensitivity analyses reveal that carbon pricing alone has limited influence on routing decisions, whereas optimizing emissions under cost constraints leads to more sustainable but more centralized logistics patterns. These findings indicate a structural misalignment between cost-efficient and environmentally optimal strategies. The study underscores the importance of route-specific eligibility rules and operational constraints, such as minimum vehicle fill rates, to support logistics decisions aligned with sustainability goals. ...
Master thesis (2025) - E.M.C. van Dijk, J.E. Goncalves, Martijn Duineveld, J.M. Vleugel
Norway is widely perceived as a global frontrunner in environmental responsibility and sustainable development. Yet, tensions arise when national green ambitions translate into local land-use decisions shaped by competing values and aims. This thesis explores such a conflict on Askøy, an island near Bergen. Despite several objections and years of local resistance, a proposed sustainable urban development project called Kildn has been dominating the municipal planning debates. Kildn is promoted by the developers “as a new way of thinking” to become the world’s first zero-emission cruise harbour and fjord metro hub. However, the project is planned to be built on Askøy’s last untouched coastline, raising concerns about nature conservation, local identity and democratic participation. To explore how this debate unfolds, the study applies a critical planning perspective and analyses how different actors – including politicians, citizens, and developers - discursively construct their aims and mobilise support through texts, discursive strategies and engagement with social practices in multiple public arenas. Through a qualitative discourse analysis of interviews, social media, and documents, the research formed a nuanced and in-depth understanding of how underlying power and contextual dynamics shape the knowledge, legitimacy and influence of the discourses within the planning process. The findings reveal that planning is far from a neutral or purely technical process. Even in a democratic, consensus-oriented society with embedded participatory practices like Norway, hidden power dynamics and contextual dynamics determine whose voices are heard and whose knowledge is perceived as legitimate. However, the study also shows that marginalised groups can influence planning debates by organising strategically, building alliances, demonstrating dedicated leadership and creating visibility across various platforms. This thesis highlights the need for urban planners to recognise how discourse and power operate within complex contexts to shape planning outcomes, and to develop more inclusive decision-making processes that respond effectively to public value conflicts. ...

A Case Study at Amsterdam Airport Schiphol

Winter weather can significantly disrupt airport operations, leading to flight delays, cancellations, and substantial economic losses. Proactively forecasting airport capacity during snowfall is essential to ensure timely flight cancellations and maintain operational continuity. While aircraft stand availability is a key determinant of overall airport capacity, data-driven insights into this process are lacking. This study addresses this gap by developing a forecasting model to predict aircraft stand snow removal capacity, using Amsterdam Airport Schiphol as a case study. A classification algorithm is employed to extract operational cleaning activities, cleaning, traveling, and idle periods, from historical radar data, enabling the assessment of current cleaning performance. Based on these insights, a simulation-based model was developed to forecast stand cleaning capacity under anticipated operational and environmental conditions. The model’s flexible design allows users to adjust scenario-specific input parameters, such as team availability and capacity restrictions, facilitating tailored scenario analysis. By simulating the alignment between available cleaning capacity and inbound flight schedules, the model identifies potential queuing situations and facilitates the assessment of additional capacity restrictions, supporting more informed capacity planning. ...

A Case Study in The Hague Neighborhoods: Dreven, Gaarden, and Zichten

Effective waste management is critical for urban sustainability, yet decision-making in this domain is often divided due to diverse stakeholder interests. This study applies the Multi-Actor Multi-Criteria Analysis (MAMCA) to evaluate waste collection alternatives for the redevelopment of the Dreven, Gaarden, and Zichten neighborhoods in The Hague. Stakeholders—including the Municipality of The Hague, Staedion (housing corporation), Haagse Milieu Service (waste collection service), and Heijmans (developer)—were engaged to define key evaluation criteria: cost, space usage, ease of use, sustainability, and implementation feasibility. Five alternatives were assessed: (1) the existing Underground Residual Waste Containers (ORACs) as a baseline, (2) Indoor Roll Containers, (3) Indoor Press Containers, (4) Press Underground Containers (ORACs with compaction), and (5) an Underground Waste Transport System (OAT). The results indicate that press underground containers (ORACs) are the most supported alternative across stakeholders, offering a balance between cost efficiency, operational feasibility, and sustainability. In contrast, indoor roll containers received the lowest evaluation due to high operational costs and inefficiencies. Despite this, indoor roll containers are currently being implemented in the first newly constructed buildings in the redevelopment area. This underscores the necessity of using MAMCA in waste management decision-making, as it enables a structured, multi-stakeholder approach that can lead to more broadly supported and efficient solutions. The study demonstrates MAMCA’s potential as a decision-support tool, integrating stakeholder preferences and structuring complex multi-criteria evaluations. The findings provide a foundation for the data-driven, phased implementation of press underground containers and emphasize the importance of stakeholder collaboration in waste management decision-making. ...
Master thesis (2024) - B. Szarszewski, J.M. Vleugel, M.B. Duinkerken, R.R. Negenborn, J. van Peursen
Accurate forecasting in Reverse Supply Chain (RSC) management is crucial for the semiconductor industry, particularly for companies like ASML, which must efficiently manage the return flow of defective machinery parts. This study addresses key gaps by developing and evaluating time series-based forecasting models tailored to ASML's RSC. Using a modified ABC-analysis, parts were categorized based on defect frequency and economic impact, focusing on the most critical components. The research applied and optimized models including SES, ARIMA, ARIMAX, and LSTM, using five years of historical defect data. The analysis showed that LSTM models excel in high-frequency (weekly) forecasts for parts with frequent early-life defects, achieving an average mMAPE of 26.32\%. ARIMAX models performed best for lower-frequency (monthly) data, particularly in sparsely represented classifications, with mMAPE as low as 4.31\% to 10.80\%. Despite a higher mMAPE of 85.42\% in one outlier, ARIMAX emerged as the most balanced model, offering a practical trade-off between accuracy and computational efficiency. Furthermore, the study highlights the computational efficiency of ARIMAX, which, although more demanding than SES, provided a favorable balance, with ARIMA and LSTM being more resource-intensive. These findings demonstrate ARIMAX's suitability for long-term forecasting and broader trend analysis, making it the preferred model for ASML's RSC. This research provides a robust, data-driven framework that enhances inventory management and capacity planning, making it possible to predict return flows with low error rates on a monthly basis, particularly in high-tech industries where many defective parts are returned. Future research should incorporate additional dynamic variables, explore hybrid models, and refine data splitting techniques to further improve predictive accuracy and support sustainable supply chain operations. ...

An exploratory research on practices performed within the system of circular material hubs in the Netherlands: its challenges, opportunities, potential future developments and the connection to architects

Master thesis (2024) - I.M. Köhrer, M.F.M. van Uden, Bas van Vliet, J.M. Vleugel
Purpose: The construction industry is responsible for great amounts of resource consumption, waste generation and both carbon and greenhouse gas emissions in the European Union. The currently still predominant linear mindset of take-make-consume-dispose must shift to reduce the industry’s environmental impact and enable the transition towards a circular construction industry. Circular material hubs facilitate more circularity by collecting, processing, and redistributing secondary building components to make them available for another life cycle. In literature, little can be found about the system circular material hubs are embedded in and their connection to architects. This study investigates the system of circular material hubs in the Netherlands, its challenges, opportunities, and potential future developments in the transition towards a circular construction industry. A special focus is placed on the role of architects within this system, as a circular construction industry also needs designers to include secondary building components in designs. The Netherlands is one of the top nations in the reuse of secondary raw materials and therefore provides as an exemplary setting for this exploratory research.
Methodology: An exploratory, qualitative research approach was chosen. Fourteen semi-structured interviews were conducted with representatives from circular material hubs, architects, as well as experts in the fields of circular economy, circular construction industry and construction logistics. Practitioner interviews aimed at identifying practices performed within the system of circular material hubs, and detecting challenges, opportunities and potential future developments as perceived by practitioners in the field. Expert interviews were conducted to validate the information gathered through literature review and practitioner interviews.
Findings: The research found four practice bundles which are important for the system of circular material hubs. These practice bundles are acquisition practice, processing practices, sales practices, and material harvesting practices. Within these practice bundles, different practices and performances of these practices were identified. The practices influence each other. Which building components are acquired influences which processing practices need to be performed. The type of building component also influences the sales practice as different building components target different groups of clients and are sold through different communication channels. It is also crucial whether the building components are sold offline or online. The online marketplace of Insert was found to be particularly helpful, as it is specifically designed for the construction industry and used by circular material hubs as well as architects. This shows the influence of the choice of communication channel on a circular design practice and scouting practices. By providing as much information as possible about the secondary building component at hand, circular material hubs also facilitate a circular design practice. Additionally, challenges, opportunities, and potential future developments of the system of circular material hubs were identified. Challenges the system faces are related to uncertainty and irregular assortment, guidelines, costs, and the provision of guarantees, while opportunities are governmental decisions, the provision of information and the use of shared online marketplaces. Missing collaborations are both a challenge and an opportunity. Future developments are primarily related to changes in the provision of secondary building components.
Research limitations: The limitations of this study are that social practice theory was not applied to the entire research as it is not suitable for the assessment of challenges, opportunities, and potential future developments. A greater variety of circular material hubs, not in number but in their field of activity, could present a different view on the system. Semi-structured interviews also always have certain limitations. Identifying the practices while they are being performed could also have led to more in-depth results.
Originality/value: By providing a comprehensive view on the system of circular material hubs in the Netherlands, this research helps to understand the dynamics within the system and allows the identification of potential interventions based on the practices that constitute the system. ...
Master thesis (2024) - T.B. van Muiden, G.P. van Wee, J.A. Annema, J.M. Vleugel
This paper examines the potential for privatising the port of St. Eustatius to achieve self-sustainability through the strategic port planning process. Design criteria were established based on a PESTEL, SWOT, and trend analysis, resulting in the development of four strategies. These strategies include enhancing port resilience, creating a transshipment hub, accommodating cruise ships, and enabling the docking of recreational vessels. Based on the strategies, opportunities for privatisation were identified according to the different rationales. Within the different strategies, opportunities for privatisation and a corresponding adaptation of the administrative model are possible. However, the need for large infrastructure investments could hinder the willingness of private parties to invest. Therefore, a public-private partnership is seen as a possible alternative to share the financial risks and also enable the government to retain control. ...
Inland waterway transport is a low CO2 emission alternative to road transport. A shift towards more inland waterway transport could also help reduce road congestion and noise pollution. Infrastructure bottlenecking, particularly at locks, is part of the reasons preventing this shift. Congestion is leading to delays. Locks can be physically improved, or the passage of the vessels through the locks can be optimized through scheduling. Recent work introduced a novel switching-max-plus-linear system approach to scheduling vessels passing through networks of waterways and locks, also introducing a novel routing component to the scheduling problem. Switching max-plus-linear systems are a convenient way to model scheduling systems using max-plus-linear algebra. The switching-max-plus-linear model only considered locks with a single chamber that can only process one vessel at a time. Additionally, it only considered four specific waterway network configurations, rather than any arbitrary network configuration. Real locks can have multiple chambers, and they can process multiple vessels at the same time if they are placed according to regulations in the two-dimensional space of the chamber. The scope of this report was then to build upon this switching max-plus-linear model by adding support for arbitrary network configurations, and multi-chamber, multi-vessel locks with proper twodimensional ship placement, to answer the main research question: How can multi-vessel, multichamber locks with ship placement be integrated into the SMPL IWT scheduling model? Three mathematical scheduling models formulated as SMPL systems were introduced, each subsequent model building on the previous one. The first introduced support for arbitrary network configurations. The second introduced support for multi-chamber locks and allowed vessels to pass through lock chambers at the same time, provided that their assigned one-dimensional sizes fit into the assigned one-dimensional capacity of the chamber. The third introduced support for twodimensional ship placement through a Tetris-like placement sequence also modeled as a switching max-plus-linear system. The models were translated to mixed integer linear programming models, and arrival time and arrival time offset objectives were added, so they could be used as the rules by which a scheduler would build and solve offline scheduling optimization models on a case-by-case basis. Auxiliary objectives to promote vessels slowing down, rather than waiting stationary in the waiting areas, were also added. The models were all found to be working as intended and implemented correctly through the use of a number of verification cases and tests. Complexity tests showed that the solution times for all three models already became larger than a practical limit of 15-20 minutes for simple scenarios with 10-15 vessels. A heuristic model that mimics how vessels are assigned to lockages in practice was built. Comparisons to the scheduling models on the verification cases showed negligible differences for the models in single-lock cases, but it indicated that the multi-vessel, multi-chamber models may outperform practice in multi-lock cases. Future research is recommended to focus on online optimization to account for disturbances, distributed optimization to reduce calculation times, and validation of the model’s performance with real data. ...
Master thesis (2023) - R.A. Slingerland, W.W.A. Beelaerts van Blokland, D.L. Schott, J.M. Vleugel
This master thesis focuses on the effect of variabilities in a Power & Free conveyor system on the flow continuity by an analysis on the product, process and production level (3P), a discrete-event simulation model and the theory of Cyber-Physical Production systems (CPPS) to control the product flow. Scenarios were evaluated with this model and the results show the effect of performance increase when variability decreases. Requirements are set to come to real-time control by developing this model into a digital twin as part of a CPPS. It can be concluded that the discreteevent model can be used to predict the performance and take control measures accordingly, subsequently real-time control is possible by implementing real-time sensor measurements in the model, thereby developing the model into a digital twin. ...
Master thesis (2022) - E.W.A. Tets, W.W.A. Beelaerts van Blokland, R.R. Negenborn, J.M. Vleugel
In this day and age sustainability is becoming increasingly important. Even though the airline business is not the first thing which comes to mind when regarding sustainability there are huge efforts in play to extend the life of airplanes and its corresponding components. This is done via remanufacturing. Remanufacturing can here be defined as:” Returning a used product to at least its original performance with a warranty that is equivalent to or better than that of the newly manufactured product” (Gunasekara, et al., 2018). Even though numerous attempts using traditional techniques like Lean have been tried at KLM E&M, none have yielded the long term desired results, which is why a different approach is needed. Remanufacturing brings numerous problems with it, unknown to traditional manufacturing (Guide Jr & Daniel, 2000). These problems result in the operational level of the organisation not having control over the process, which leads to subpar performances. Furthermore, a gap originates between higher level management and the operations, which leaves a lot of potential uncovered as well as discourage operational level progress. The proposed model is designed to help gain control over an uncontrolled process, improve its performance and sustain the newly found control, which is also the purpose of this research. This is all achieved using a more bottom-up integral approach. This proposed model is combined with the operational lean maturity model developed by Maasouman (Maasouman, 2015), in order to create a Remanufacturing Process maturity model, which indicates the maturity level of each aspect used in the Remanufacturing Process control model, resulting in a model which has both quantitative and qualitative aspects. ...

Towards effective policy making

Master thesis (2022) - M.W.F. Roos, G.P. van Wee, J.A. Annema, J.M. Vleugel
There is an ongoing trend of urbanisation, and cities are becoming more and more crowded. In 2014, 46\% of the population of the OECD countries lived in urban areas. Whereas the growth of cities was previously mainly an expansion, the growing population is now increasingly leading to densification. Since 2007, more than half of the constructed houses in the Netherlands has been placed within the existing built area. In the most recent period (2016 to 2018), the share even was 56 per cent. There is a controversy between the individual desire to have a car and the contrasting desire to remove cars from the outdoor space in inner cities. Moreover, land-use policies positively contribute to the environment by managing car use and improving accessibility. Identifying success and failure factors regarding the used strategy and implementation provides feedback to evaluate the strategy. The hub can combine different aspects of mobility, help remove cars from the streets, promote car-sharing and electric vehicles and therefore be an important part of the solution. However, the set-up and implementation of a mobility hub is a complex endeavour where many stakeholders are involved, and sound policy is crucial. In the structured search performed to identify success and failure factors of mobility hubs, an important finding was that the literature is heterogeneous. The gaps found between theory and practice concern the financial feasibility, the incentives for alternative transport, good relationships and clear responsibilities of stakeholders and attention for increasing the utilisation rates of transport modes. Concerning the barriers, competing goals of modal shift and EV adoption need attention, and again, stakeholder responsibilities were not completely clear. ...
Master thesis (2022) - R.B. Jebbink, G.P. van Wee, J.A. Annema, J.M. Vleugel, Jan Zekveld, Yannick Enting
This research explored potential designs of an innovative mitigation strategy to combat the aircraft-produced ultrafine particle (UFP) concentrations at Amsterdam Airport Schiphol (AMS). This technique is based on the principle that fine water droplets are able to encapsulate dust and fine particles, which clump together and eventually descent to the ground. The reduction of airborne particle concentrations is expected to have a significant effect on the health of (platform) employees, which makes it an interesting strategy to further investigate. A wide variety of stakeholders, from both the aviation industry and the academic world, were interviewed about the important design components that need to be incorporated in a potential mitigation system, as well as essential requirements that the system needs to comply with. A system that integrated the cold start of the aircraft engines as the most suitable moment and the introduction of remote starting positions as the most optimal location for the implementation of UFP mitigation strategies, contributed to the proposed conceptual design for AMS. A system alternative in which the water droplets are directed into the jet engine outlets by spraying cannons was discussed for a close-up mitigation strategy, while an alternative in which a screen of water droplets is created to absorb the jet blast with emissions was established for the mitigation strategy at a further distance. The assessment of the conceptual system design, on its feasibility, viability and desirability, showed that the UFP mitigation system could have a desirable impact on Schiphol’s environment on the short-term. However, the possibilities of implementing remote starting positions at AMS and the impact that the system has on the starting capacity and the turnaround time should be further investigated to increase the system’s feasibility and viability. ...