The environmental impact of additive manufacturing (AM) in consumer-electronics repair remains largely unexplored. AM allows on-demand production of spare parts, making it possible to repair products without available replacement parts (RPs). However, its per-part impact is higher than conventional injection molding (IM). When no digital part exists, redesigning it—such as through the 3DPfR framework—often requires multiple testing and printing iterations, further increasing its environmental impact. Literature focusses on either emphasizing qualitative approaches like AM-enabled sustainable design strategies or quantitative life cycle assessment studies that overlook these trade-offs and the broader system dynamics. Few take a systematic, quantitative approach to evaluating AM in the context of product repair. This study addresses this gap through a life cycle assessment case study of the Philips Senseo HD6569/00 coffee machine.
The following input variables are defined: lifetime extension, part mass and five responses to product failure (RtPF). The five RtPFs are compared in this study are: product replacement (Replace), repair using a single injection molded RP (IMRP), IMRP including n overproduced IM RPs (IMRP-n), on-demand RP production using a pre-existing AM-ready digital model (AMRP), and using the 3DPfR framework to design an RP for AM and requiring n printing iterations to achieve an acceptable part (AMRP-n).
LCA is employed as the primary method due to its ability to systematically and quantitatively assess environmental impacts across an entire product lifecycle. The study uses ReCiPe 2016 (Hierarchist) to evaluate environmental impact midpoint categories, with the functional unit defined as “providing one year of coffee machine use for a consumer in the Netherlands”. The study takes a cradle to grave approach, including a logistics scenario, but excludes the machine’s use- phase impacts. The next phase of the study involves performing a sensitivity analysis and contribution analysis as well as depicting tipping points between different repairs compared to product replacement.
The study defines one alternative as environmentally ‘favorable’ over another if it has a lower impact score in all impact categories compared to its alternative. Results identify electricity consumption during printing, 3D printer production, and RP material impact differences as key drivers of AM’s increased environmental impact over IM. As a result, AM-based repairs always lead to a higher environmental impact compared to IM-based repairs. This difference becomes more evident when additional AM print iterations are required, or the number of overproduced IM parts increases. When comparing repair to product replacement, IM-based repairs are far more likely to be environmentally favorable over product replacement compared to AM-based repairs. Therefore, the number of IM overproduced parts is not considered a sensitive variable, whereas the number of print iterations is. However, the exact tipping point is highly depending on the input variables.
IM-based repairs should be prioritized whenever available. If no IM RP is accessible, minimizing the number of AM print iterations is crucial, with single print-on-demand manufacturing being the most favorable option. When neither an IM RP nor an on-demand AM RP is available, a part can be redesigned using the 3DPfR framework. In this case, the environmental favorability of repair over replacement depends on the number of required print iterations, part mass, and expected lifetime extension, and careful assessment should be made. While the scenario evaluation tool developed in this study provides insights into these trade-offs, its findings are highly context dependent. If AM RPs designed via 3DPfR contribute to an open-source, on-demand manufacturing library, their broader sustainability benefits may justify their initial environmental impact.
The impact of overproducing IM RPs is less significant compared to the number of AM iterations. Specifically, for the same part mass and lifetime extension, producing 10 IM RPs or performing 2 to 6 AM print iterations can be environmentally favorable over product replacement, depending on the packaging type used for transporting the IM RPs.

The pressing sustainability challenges have underscored the need for transformative measures within the global economy. The circular economy presents itself as an alternative to traditional linear models and promises transformative change. However, this transformative change is hindered by the remnants of linear thinking embedded in many circular economy definitions. To address this challenge, this research explores conceptual metaphors as a valuable tool for reshaping the understanding of the circular economy. Among these, the forest metaphor offers a compelling perspective, framing the circular economy as a forest. Yet, the potential of the forest metaphor remains theoretical. To determine its ability to drive the transformative change required for a circular economy, it is essential to translate the forest metaphor from theory into practice. Achieving this translation requires the practical implementation of the forest metaphor. According to the Law of the Few, certain key individuals play a disproportionately large role in the successful implementation of novel concepts. Therefore, this research aims to answer the question: How can the individuals most likely to adopt and diffuse the forest metaphor—"the Few"—be distinguished? The research is conducted in two phases. Phase 1 involved profiling the Few through a combination of literature review, expert consultations, and a validation process with focus groups. Nine key themes with 23 profiling criteria were identified, which were synthesized into a framework of three main categories, requiring an individual’s capability, motivation, and situational alignment to fit the profile of the Few. Phase 2 focused on selecting the Few within an organization by translating the profiling criteria into an assessment tool, developed through stakeholder mapping, co-creation, and testing with a small participant panel. The tool uses one question per criterion to assess individuals against the profiling criteria to determine their alignment with the profile of the Few. The results suggest that while the framework provides valuable insights into the profile of the Few, the Few might be more effectively viewed as a dynamic group, with different individuals potentially contributing unique strengths at various stages of the adoption and diffusion of the forest metaphor. As for the assessment tool, the results offer a useful starting point for identifying these key individuals, though its broad focus and reliance on a single question per criterion might limit the depth of its assessment. Therefore, it could function best as an initial filter, paving the way for a multi-stage evaluation process. In conclusion, through the profiling framework and assessment tool, this research provides a method to distinguish the individuals most likely to adopt and diffuse the forest metaphor. This represents an initial step toward bridging the gap between its theoretical potential and practical application, enabling its introduction within organisations.

Biogenic reefs built by mussels, oysters or other reef-building species are one of the most important biodiversity hotspots for estuarine and marine ecosystems providing food, shelter, and breeding grounds for a wide array of species. In the North Sea, one of the most important biogenic reef builders and ecosystem engineers is the European Flat Oyster. However, due to harmful fishing practices, habitat destruction and diseases, this once-abundant bivalve is now ecologically extinct and cannot provide crucial ecosystem services. If left without active intervention, oyster reefs have too few chances of regeneration, due to the current state of the seafloor in the North Sea and too few individuals in the environment. Therefore, active intervention is needed to bring back the shellfish reefs in The North Sea. Offshore windmill farms provide a refuge for marine ecosystems from fishing activities, which poses an important opportunity for biogenic reef restoration practices.

To understand the context of biogenic reef restoration better, multiple interviews with marine biology and ecology experts from ARK were conducted followed by a literature review and two field trips related to young oyster deployment to The North Sea. The gained insights were used to create a list of 12 design criteria grouped into four categories: Oyster survival, Scalability, Broader ecological success, Handling & deployment. According to these criteria, most of the current practices underperform in scalability due to high manufacturing, and operational costs, or provide inefficient oyster protection which hampers the success of shellfish reef restorations. Therefore, the design challenge to improve scalability and oyster protection has been chosen as the priority.

Multiple design directions and ideas have been explored using Research by Design approach while employing Whole System Mapping and Biomimicry methods with Low- and high-fidelity prototypes. Using an iterative approach and evaluating the design ideas, the solution space has been narrowed down to a final design, the unit: two steel frame gabions are connected in a double-diamond position and placed between two display pallets with all assembly tightly secured with a cotton lashing. Multiple assemblies are connected in a row with a leading rope attached to an anchor. When the ship sails, the anchor is thrown out on the seafloor and eventually pulls all units down to the seafloor. The final design was evaluated according to the same 12 criteria. In comparison to previously discussed solutions, the final design is more scalable in terms of costs and time for larger marine restoration areas and focuses on finding balance throughout the design criteria instead of being only effective in certain aspects. In addition to introducing back the Flat Oysters, the new structures provide various microhabitats for a wide array of other benthic species to grow or shelter from the water currents, amplifying positive effects on the marine ecosystem. Several theoretical and structural integrity tests have been done to determine the effectiveness of the new design. Further research, such as offshore field studies, is needed to determine how this new design affects young oyster survival and other benthic species.

The goal of this graduation project was to investigate if 3D printing could serve as a promising alternative for manufacturing spare parts needed for the re-manufacturing of diesel injection pumps. This project was conducted under the EU ReCiPSS project, along with the support of Robert Bosch GmbH. The proposition was investigated on three levels and posed the following research questions:

1.Can 3D printing produce spare parts for the pump at an acceptable cost and quality level compared to the existing manufacturing methods? (Feasibility)
2.Does spare part 3D printing make business sense for the Automotive Aftermarket Division of Bosch to pursue as a remanufacturing strategy? (Viability)
3.Is 3D printing for spare parts more environmentally friendly compared to the existing manufacturing methods? (Sustainability)

To answer these questions for the entire VP30 pump and fuel injection pumps in general would have been difficult. Thus, tools such as the Disassembly Map and the Hotspot Mapping tool were used to identify potential parts within the pump for which this initial investigation could take place. Using functional importance and environmental impact as criteria, the selection of two parts, an aluminium Locking Cover and an alloy steel Cam Plate were made.

Visits to the remanufacturing facility and Bosch’s 3D Competence Centre opened doors to investigate the technology, its limitations, organisational barriers, and future potential. The metal printed parts arrived and were analysed on the three pillars mentioned.

The investigation found that metal 3D printed parts can meet the desired performance specifications. However, post-processing treatment such as annealing, case hardening and some machining might be required for specialised functions. The costs of metal 3D printing are not yet competitive with conventional manufacturing and are viable only for specific scenarios. These scenarios take the shape of lack of suppliers, urgent part demand, high tooling costs, and so on. Moreover, the non-competitive cost also brings to fore the organisational barriers within Bosch. Primarily, the automotive release procedure which requires significant investment of time and money to make a change. Lastly, on the sustainability front, middle volume production (~200-1000 units) was shown to be more sustainable than conventional manufacturing for the same volume.

The investigation shows that in 2022, 3D printing metal spare parts is feasible but needs specific scenarios to be viable and sustainable. However, with improvements in technology and greater acceptance of 3D printing as a core industry technology, these pains can be resolved and allow for better and long-lasting products with lesser environmental impact. The advent of the 2030’s will be exciting in this regard.

This Thesis report covers the creation and validation of a spreadsheet-based self-declared quantitative cost of ownership tool. The accompanying labelling Scheme informs customers about the Total Cost of Ownership (TCO) of their products with a focus on the Repair Costs. The Total Cost of Ownership Tool (TCOT) offers customers a better comparative potential with regard to the longevity of products.

The tool distinguishes itself from currently existing initiatives and tools for it provides a quantitative scoring of the cost of ownership and repair. This quantitative scoring is detrimental to the fair comparison of products. Previously existing tools mainly provided a qualitative grading. For this concept to work product manufacturers will be obliged by legislative organs to fill in the TCOT to get a corresponding label that needs to be displayed at the place of purchase. The tool in return provides the manufacturers with valuable data on how to improve their products. The newly obtained quantitative data can be used by legislators to assess the progress of longevity of products to assess the effectiveness of the newly adopted TCOT legislations.

To explore this solution space the cost of ownership and repair needed to be expressed in a mathematical formula. Thereafter the factors that influence the variables in this formula needed to be quantitatively expressed. One major qualitative element however remained. The grading of the chance of a successful repair was performed by including conditions and criteria of the French Repairability Index (FRI).
The development of the tool relied on iterative cycles of performing case studies with data on smartphones. The early iteration cycles revealed that small variations in the input variables resulted in significant differences in the outputs. Not only was the available literature on some of these variables limited. Often sources provided contradicting figures making conclusive results difficult to obtain. To test the technical aspects of the tool and assess the individual impacts of the input variables, different scenarios were explored. This provided insights into how the tool deals with the varying input data. The outcome of these tests fell within the bounds of expectation and revealed what further steps need to be undertaken to further develop the TCOT.

The quantitative display of these often unknown and intangible ownership costs provides the customer with the information that she needs to better be able to choose a longer-lasting product. This newly acquired transparency towards the customer can help legislators nudge manufacturers into producing longer-lasting products. The further development of the tool and its accompanying label scheme will help with the transition towards the envisioned circular European Union by 2050

The current ‘take, make, waste’ linear economy has caused many ecological and social problems; that’s why the circular economy aims to close the loop so businesses can thrive while natural resources sustain and regenerate. Metabolic, a sustainability consultancy that helps clients transition towards the circular economy, recognizes that a circular product can only exist within a properly functioning circular system. Therefore, they adopt system thinking, a thinking skill that perceives parts of a more extensive system as intertwined components rather than independent entities (da Costa Junior et al. 2019), with science-based analysis in their project work.
However, collaborations between stakeholders are essential to achieve systemic changes since they might all hold different values, interests, and world views on a system. Metabolic’s current ‘science-based system thinking’ methods can be improved by engaging and building upon those collaborations. Systemic design provides frameworks and methods to create a shared understanding that mutual agreement can emerge among actions to be taken. Besides, designers’ ability and methods to synthesize, visualize, and create can complement system thinking in co-creating circular economy solutions among stakeholders. Therefore, this graduation project explores how systemic design and other design methods could help improve Metabolic’s circular system design process.
The outcome of this project is a Circular system design process with multiple sessions, activities, and tools developed for Metabolic to apply in their future projects. Additionally, a guidebook (Ch. 5) was written for Metabolic members to learn and get the essential preparation for adopting the tools.

In this Master Thesis the potential of Additive Manufacturing on-board vessels of Heerema Marine Contractors is looked into, with the goal to design a recommendation for implementing this technology. Heerema is an offshore construction company that is intrinsically motivated to improve their sustainability. They transport, install and remove all types of offshore facilities. All Heerema vessels have a warehouse on-board, containing spare parts. Spare parts are parts in-stock that will be used to maintain the vessel or execute projects. In total the warehouse contains 300.000 parts, with an average value of 13.000.000 US$. The total weight of the stored material is 1.400.000 kg. If a needed spare part is not in-stock, it is ordered and brought to the vessel. Both actions take up a lot of time and could risk a project being stopped, which influences the economic pillar of the Triple Bottom Line consisting of people, planet and profit. Having this many parts on-board, and always ordering a ‘new part’ when something breaks, is not seen as a sustainable project execution. Especially taking into account the possibility of repairing. Next to that, extra transports or air freights are needed to get parts on-board, which influences the sustainable pillar of the Triple Bottom Line. In some cases, parts used to be produced by suppliers that do not exist anymore, which makes it hard to order new ones or obligated to purchase packages. The preferred situation for Heerema would be to use Additive Manufacturing as an additional production method for spare parts. For the implementation of this technology, a sufficient quality of the printed parts is desired. Sufficiency for critical parts has to be qualified by external certification organizations. Sufficiency for non-critical parts is reached once it functions within the used application. Next to the quality of the prints, the time it takes to print a part is important. Both quality and time depend on the performance of the 3D printer, which will influence the adoption of the crew. The preferred situation can be seen as the goal Heerema if aiming for. To reach this goal, a Roadmap is recommended. This Roadmap is designed as being the most suitable way of implementing and using 3D printing on-board of their vessels. The Roadmap is based on three different phases: The Research phase, The Printing phase and The Opportunities phase. Within these phases, the printing phase exists of two sub-phases: a plastic and a metal print phase. Each printing phase exists of a testing phase, a limited use phase and an expansion phase. The transition from one phase to another is based on a stepwise approach to lower the risks that could occur while implementing a complex innovation. The stepwise approach is based on the level of trust among the vessel crew towards the level of complexity of the implemented innovation. The conducted research supports the proposed solution that leads to the preferred situation. The solution is assessed according the three aspects of the Industrial Design Engineering domain: Technology, Human Values and Business.
The solution is shown to be feasible due to the chosen hardware, the study on printable spare parts, 3D print studies and mechanical tests at the TU Delft.
Additionally, the solution is shown to be viable due to relative low investment costs, a decrease in man-hours and transports and a waste reduction based on Value Stream Mapping. Also, the solution is shown to be desirable due to the collaboration with current users, a promising partnership with Layertec and the fit with the sustainability aims of Heerema. The thesis is enclosed by mentioning the research limitations, reflections, recommendations and further research for Heerema.

Materiom is an online initiative that has been growing an online open source database of bio-based material recipes over the last couple of years. A new category of recipes to be found on this website is the category of bio-based 3D printable materials. The first 3D printable material recipe to emerge in the database was developed at the TU Delft. Since then the recipe was further developed into an alginate mussel shell composite. It was time for the next step: How can more of these kinds of materials be developed? Are there any ‘universal truths’ to be found in developing these materials and how can makers/designers be guided in this process? To tackle this problem a multileveled analysis was performed. A literature review of 3D printing with bio-based materials showed that in different fields of expertise, ranging from the medical field to the field of food, the first steps had been made into printing with bio-based materials. Printing experiments were then performed with a selection of binder materials mentioned in these papers. With iota-Carrageenan and kappa-Carrageenan in combination with different kinds of fillers such as rice starch and ground cacao shell, succesfull prints were made. Furthermore, interesting hand-printing results were obtained with chitosan and alginate. More importantly, however, an indicative range of material ratios was found that could help future material developers save time in their search. Finally, some basic guidelines for the printer set-up regarding nozzle size, print head speed and extrusion speed were formulated based on the findings in the experiments. These results led, together with the insights gained from analyzing makerspaces, cookbooks and the Materiom website, to a design proposal for an online material development tool. Currently the Materiom website provides ready-made recipes. As noticed during the analysis phase, however, not every experiment leads to a complete recipe. Also, based on the experience of a material developer, complete recipes are not always what is needed. Recipes can be inflexible and hinder experimentation and innovation. The material development tool provides therefore room for data on different levels. This means that the community can share a larger amount of data and it leaves room for more experimentation and innovation. This idea is brought in practice by dividing data into three different parts: Material information, material compatibility information and complete recipes. Together with a formulaic recipe that gives a starting point for experimentation and printer set-up guidelines, material developers have a range of tools that they can use according to their needs and likings for new material development. And when the experiments have been carried out, the data can be shared with community even when the results were not satisfying and thus saving time of their successors.

Additive Manufacturing (AM) is undergoing a radical evolution. AM businesses such as Ultimaker (UM) are speeding up industrial production through digital design and local manufacturing to enable industries to produce “what they need, where they need it, and when they need it” (“Ultimaker”, 2019), while also being cost-effective. AM is perceived as a key sustainable technology as it enables efficient design and is believed to make less waste (“AMFG”, 2020), thus putting Ultimaker in a position to offer sustainability enhancements for their clients’ manufacturing processes. One topic of debate for AM sustainability, and the topic of investigation for this thesis, is whether bioplastics are more sustainable than fossil-based plastics for Fused Depositon Modeling (FDM) 3D Printing. Although PLA, a commonly used FDM material, is bio-based, it was hitherto unclear how much using this material and other BBPs can reduce the ecological impact of the 3D printing (3DP) process. This investigation was conducted in three phases- First, gaining an understanding of the context through literature review, market analysis and expert interviews. Second, material tests conducted to compare energy use and material properties of 3DP filaments. Third, a synthesis of findings from the first two phases into a material guide and recommendations for reducing the environmental impact of 3DPrinting. Whereas polymers are classified as bio-based/fossil-based and biodegradable/non-biodegradable, the 3DP filament materials available in the market often contain additives, fillers, or other polymers which make them difficult to categorize in a single type (Rohringer, 2020). Hence, a variety of polymers were selected for conducting material studies- including 3 UM-standard filaments, and 5 new filaments. Both environmental and functional properties were studied. For environmental impacts, literature showed that across the different parts of the 3DP filament life cycle, electricity use of the printer is the biggest contributor to ecological impact (Faludi et al., 2015). This motivated the investigation of energy use of a UM printer while printing selected materials. For functionality, expert interviews highlighted tensile properties, dimensional accuracy, and ease of printing as the most important criteria in the material selection process- thus motivating comparison tests for the same. An energy use comparison test revealed that electricity use is mainly influenced by build plate heating. More research is recommended to minimize build-plate heating for UM printers through solutions such as insulating the build chamber, or localized heating of build plate. The print quality and tensile tests affirm BIOPETG as a potential drop in replacement for UM-CPE. For both tests, new materials performed slightly worse, albeit often at acceptable levels, as compared to UM-standard materials. However, this can be attributed to the rudimentary level of print process optimization conducted for the new materials. Thus, it is recommended that these materials go through an elaborate optimization process in order to gain a more accurate impression of functional performance. As the final outcome of this investigation, the data collected was compiled into a material guide containing material properties and sustainability indicators. This visual can be referred by end-users like engineers, designers and production professionals to make appropriate material choices for their applications.