The production of a heavy-duty road vehicle is a major contributor to the overall financial cost and environmental impact of the vehicle. In recent times, closing the material loops using circular practices has emerged as a promising approach to reduce the environmental impact of the vehicle production. The most common circular practice is material recycling, but this is a low-value process, as any embodied value in the product apart from the material refinement is lost and, even then, the recycling process might be cumbersome if the product is composed of multiple materials that cannot be easily separated. An upcoming and promising approach to circularity is remanufacturing where a product is disassembled and the constituent components are cleaned and inspected.  The components which pass the inspection are then reused in new products. This preserves the value in the reused products and not only reduces the consumption of raw materials, but also manufacturing effort. In order for the remanufacturing process to be worthwhile, some conditions need to be satisfied. Firstly, the product needs to be valuable enough for the remanufacturing effort to make economic sense. Secondly, the state of a product that is returned from a customer must be able to be ascertained with a certain degree of confidence in a quick manner. One way to evaluate the state of a returned product is by using the historical usage data of the vehicle it comes from. The goal of the work presented here is to study the feasibility of remanufacturing for different heavy-duty road vehicle components based on the economical benefits as well as the availability of data for the component in question, as well as identifying the relevant data for evaluating the remanufacturability of the component in question.

Despite the increasing availability of tools and methods for sustainable and circular product design (DfS), their uptake in practice is slow. This is also true in the automotive industry, where DfS is an important measure for addressing the industry's negative environmental and social impacts. To facilitate DfS implementation, this paper uses an analytic hierarchy process (AHP) and offers, for the first time, a classification and prioritisation of the barriers that need to be overcome when implementing DfS into vehicle development processes. Based on a systematic literature review and on an expert workshop, the top 15 DfS barrier factors were derived and divided equally into five groups, following a multi-level structure. These factors and groups formed the input for a survey-based analytic hierarchy process with 38 European industry experts. The results show that strategic issues are the most important barriers, followed by the group of operational, personal, external, and tool-related barriers. Among the 15 barrier factors identified, the top five were (1) an unclear link to profitability, (2) lack of top management support, (3) difficulties in handling trade-offs, (4) high operational costs, and (5) a lack of integration of DfS into corporate strategy. The results indicate that while external constraints already exert pressure on automotive companies, they still face particular challenges when attempting to integrate sustainability into corporate strategies and in transferring such strategies to DfS activities at the operational level. The study results may be used to inform managerial policy and further research.

Although plenty of research has been carried out to develop a multitude of sustainability assessment methods, few guidelines and criteria have been established to help practitioners and researchers find the most appropriate method for a specific case. Studies have shown the importance of integrating sustainability assessments when conducting research and development activities, but have not provided direct links to available sustainability assessment methods. To address the so-called "eco-design paradox", this paper describes a systematic classification system for the available sustainability assessment methods. To support the early integration of sustainability assessments in research and development, we inductively derived the concept of sustainability assessment levels from the well-known concept of technology readiness level. In total, 33 sustainability assessment methods were considered. We performed an expert-based correspondence analysis based on the availability of information to perform these methods and the demand for specific information at respective technology readiness level. Thereafter, a cluster analysis was performed, creating four distinct clusters which were finally interpreted as sustainability assessment levels. The provided concept supports interdisciplinary research projects in that it provides an overview of and guideline for possible sustainability assessment methods that match the respective technology readiness level. This enables researchers to integrate sustainability assessment into respective research and development projects and further modify and develop the theoretically synthetized concept based on empirical case studies.

Over the last years, academic literature has made significant progress on the development of key concepts, identifying circular product typologies, developing assessment methods, and exploring the synergies with manufacturing trends such as digitalisation or environmental management. Nevertheless, less attention has been paid on describing process model changes necessary for the implementation of circular product development. For this reason, this paper presents the circular Sustainable Product Development (cSPD) morphological field, aimed at providing implementation guidance to business and industry. It describes possible reconfigurations of the Sustainable Product Development (SPD) process model to further integrate circularity R-strategies, design scopes, design guidelines, inter- and intra-organisational actors and criteria for evaluation. With this framework, we intend to identify the most defining parameters in the process model and assign them a discrete number of categorical values so that different combinations explain the generation of prevalent circular product typologies in the manufacturing of durable goods.

Power-to-X is an upcoming sector-coupling technology that can play a role in the decarbonisation of energy systems. The aim of this study was to widen the current knowledge of strengths, weaknesses, opportunities, and threats (SWOT) of this innovative technology in the Danish context by utilizing the analytic hierarchy process (AHP) to evaluate and compare perception of academic and industrial experts. The results of this analysis indicate that the external factors such as current policy framework are more important than the internal technology related factors. Further, positive factors predominate negative ones, with academic experts indicating strengths as the most important category and practitioners' opportunities. All experts consider the country being a P2X knowledge hub as one of the most important factors, and in the given context of the Danish energy system, wind developments and Danish industrial environment, seizing this opportunity could be the biggest enabler for P2X success.

The concept of circular economy (CE) is of great interest for manufacturing companies since it provides a framework which allows them to align organisational objectives with the Sustainable Development Goals (SDGs). Corporate CE entails the adoption of several value-retention options (R-strategies) throughout companies' operations, which aim at creating, preserving and recovering the value of assets and products. The sustainable product development (SPD) process, in which around 80% of the total environmental impact of a product is determined, is employed to translate R-strategies into new product requirements. This study is aimed at investigating the implications of R-strategy adoption for decision-making in SPD. The research follows an empirical approach, combining a literature review and in-depth semi-structured interviews with product developers and sustainability experts working in companies operating in the technical material cycles of the CE. Thus, implications for product dimensions, inter- and intraorganisational actors, decision-making support types and lifecycle information flows so that SPD processes further accommodate CE principles into products are investigated. This study reveals new directions to adjust the contextual factors of SPD to further align existing processes with widely expanding CE organisational cultures.

In this work, an End-Of-Life (EOL) model is included in the Life Cycle Energy Optimisation (LCEO) methodology to account for the energy burdens and credits stemming from a vehicle's EOL processing phase and balance them against the vehicle's functional requirements and production and use phase energies. The substitution with a correction factor allocation method is used to model the contribution of recycling to the EOL phase's energy. The methodology is illustrated through the optimisation of the design of a simplified vehicle sub-system. For the latter, multiple recycling scenarios with varying levels of assumed recycling induced material property degradation were built, and their impact on the vehicle sub-system's optimal solutions was compared to that of scenarios based on landfilling and incineration with energy recovery. The results show that the vehicle sub-system's optimal designs are significantly dependent on the EOL scenario considered. In particular, the optimal designs associated with the recycling scenarios are on average substantially heavier, and less life cycle energy demanding, than their landfilling or incineration with energy recovery-related counterparts; thus, demonstrating how the inclusion of EOL modelling in the LCEO methodology can significantly alter material use patterns, thereby effecting the very mechanisms enabling the embodiment of the resulting life cycle energy optimal designs.

A trend across most areas where simulation-driven development is used is the ever increasing size and complexity of the systems under consideration, pushing established methods of modeling and simulation towards their limits. This paper complements existing surveys on large-scale modeling and simulation of physical systems by conducting expert surveys. We conducted a two-stage empirical survey in order to investigate research needs, current challenges as well as promising modeling and simulation paradigms. Furthermore, we applied the analytic hierarchy process method to prioritise the strengths and weakness of different modeling paradigms. The results of this study show that experts consider acausal modeling techniques to be suitable for modeling large scale systems, while causal techniques are considered less suitable.

Improving the socio-ecological performance of products in the design stage is essential for achieving sustainable patterns of production and consumption in line with the aims of the UN Sustainable Development Goals or the EU Action Plan for a Circular Economy. However, the uptake of available methods for sustainable product development (SPD) in practice is still low. Therefore, this paper explores if and how the integration of such methods with theories and models of design can contribute to overcoming the lagging adoption of SPD practices. The systematic review that was conducted on the intersection SPD and design theory research reveals that out of 2849 peer-reviewed publications on SPD, only 27 have a design-theoretic foundation. In fact, only the Theory of Inventive Problem Solving (TRIZ) and Axiomatic Design were utilised in SPD methods. The majority of the reviewed publications address cross-functional conflicts and provide exemplary cases but mainly focus on environmental aspects. Adoptions on a large scale are not reported. We conclude that underpinning SPD methods with theories and models of design constitutes a considerable research gap and that the addressing of it has the potential to further advance their integration with conventional engineering and design tasks.

Co-simulation is a promising approach for the modelling and simulation of complex systems, that makes use of mature simulation tools in the respective domains. It has been applied in various different domains, oftentimes without a comprehensive study of the impact to the simulation results. As a consequence, over the recent years, researchers have set out to understand the essential challenges arising from the application of this technique. This paper complements the existing surveys in that the social and empirical aspects were addressed. More than 50 experts participated in a two-stage Delphi study to determine current challenges, research needs and promising standards and tools. Furthermore, an analysis of the strengths, weakness, opportunities and threats of co-simulation utilizing the analytic hierarchy process resulting in a SWOT-AHP analysis is presented. The empirical results of this study show that experts consider the FMI standard to be the most promising standard for continuous time, discrete event and hybrid cosimulation. The results of the SWOT-AHP analysis indicate that factors related to strengths and opportunities predominate.