Abstract
The concept of circular economy aims to extend the end-of-life of products by reducing or reusing products and materials, being Design a central part of a successful circular product. In line with the 6Rs strategy for circularity, Redesign (applied by eco-design practices) allows the creation of products that can be easily repaired, upgraded, or disassembled, extending their life, and fomenting a circular economy. For that reason, the aim of this research is to analyse the role of Redesign in the circularity of footwear products. Exploratory qualitative research was conducted, with five in-depth interviews with founders and R&D managers of prominent footwear organizations. Results demonstrate that most interviewed companies, which were born circular, considered Redesign practices from the definition of the product concept. In conclusion, looking at Redesign strategies holistically and through its specific sub-relationships have a major impact on the company's circularity practises.

Abstract

Abstract
In online three-dimensional packing problems where items are received one by one and require immediate packing decisions without prior knowledge of upcoming items, considering the static stability constraint is crucial for safely packing each arriving item in real time. Unstable loading patterns can result in risks of potential damage to items, containers, and operators during loading/unloading operations. Nevertheless, static stability constraints have often been neglected or oversimplified in existing online heuristic methods in the literature, undermining the practical implementation of these methods in real-world scenarios. In this study, we analyze how different static stability constraints affect solutions' efficiency and cargo stability, aiming to provide valuable insights and develop heuristic algorithms for real-world online problems, thus increasing the applicability of this research field. To this end, we embedded four distinct static stability constraints in online heuristics, including full-base support, partial-base support, center-of-gravity polygon support, and novel partial-base polygon support. Evaluating the impact of these constraints on the efficiency of a wide range of heuristic methods on real instances showed that regarding the number of used bins, heuristics with polygon- based stabilities have superior performance against those under full-base and partial-base support stabilities. The static mechanical equilibriumapproach offers a necessary and sufficient condition for the cargo static stability, and we employed it as a benchmark in our study to assess the quality of the four studied stability constraints. Knowing the number of stable items under each of these constraints provides valuable managerial insight for decision-making in real-world online packing scenarios.

Abstract
Complex systems, characterised by high interconnectedness and unpredictability, demand structured approaches to support decision-making, system integration, and operational efficiency. This study aims to develop a comprehensive understanding of these systems to facilitate the implementation of Digital Twins (DTs) in Complex Operations Environments (COEs). A Systematic Literature Review (SLR), following PRISMA methodology, is conducted and complemented by a grounded theory approach to identify, organise, and synthesise system characteristics. The result is a hierarchical conceptualisation comprising eight core categories that capture the essential dimensions of complexity, including: Process and System Interoperability, Human Relationships, Behaviour/Nature, Products and Services, Multi-processes, Performance, System Structure, and Management and Skill Requirements. This framework offers a structured foundation for designing and implementing DT-based decision support in COEs.

Abstract

Abstract
This study reflects the assumption that all links in a supply chain (SC) must share responsibility for socio-environmental issues. One of the main barriers to ensuring the sustainability of an SC is the difficulty in accessing partners' information, especially beyond the first tier. Due to the great geographical dispersion, large number of small companies, and, mainly, the growth of the fast fashion industry, the textile sector is recognised as a priority when it comes to social sustainability issues. Moreover, consumers are increasingly demanding information about the social footprint of products. Thus, this paper aims to contribute to a better understanding of how SC visibility can contribute to increasing the social sustainability of textile SCs. Using a longitudinal perspective and adopting mixed methods integrated into a design science strategy, we evaluate SC visibility in the context of two Portuguese textile supply chains, before and after the development of a technology-based solution.