The circular economy (CE) is widely known as a way to implement and achieve sustainability, mainly due to its contribution towards the separation of biological and technical nutrients under cyclic industrial metabolism. The incorporation of the principles of the CE in the links of the value chain of the various sectors of the economy strives to ensure circularity, safety, and efficiency. The framework proposed is aligned with the goals of the 2030 Agenda for Sustainable Development regarding the orientation towards the mitigation and regeneration of the metabolic rift by considering a double perspective. Firstly, it strives to conceptualize the CE as a paradigm of sustainability. Its principles are established, and its techniques and tools are organized into two frameworks oriented towards causes (cradle to cradle) and effects (life cycle assessment), and these are structured under the three pillars of sustainability, for their projection within the proposed framework. Secondly, a framework is established to facilitate the implementation of the CE with the use of standards, which constitute the requirements, tools, and indicators to control each life cycle phase, and of key enabling technologies (KETs) that add circular value 4.0 to the socio-ecological transition.

The concept of Industry 4.0 (I4.0) is evolving towards Industry 5.0 (I5.0), where the human factor is the central axis for the formation of smart cyber-physical socio-technical systems that are integrated into their physical and cultural host environment. This situation generates a new work ecosystem with a radical change in the methods, processes and development scenarios and, therefore, in the occupational risks to which safety science must respond. In this paper, a historical review of the evolution of work as a complex socio-technical system formalised through Vygostky’s theory of Activity and the contributions of safety science is carried out, for its projection in the analysis of the future of complex systems as an opportunity for safety research linked to the current labour context in transformation. Next, the Horizon 2020 strategies for Occupational Safety and Health (OSH) at the European level are analysed to extract the lessons learned and extrapolate them towards the proposed model, and subsequently the conceptual frameworks that are transforming work and Occupational Risk Prevention (ORP) in the transition to Industry 4.0 are identified and reviewed. Finally, a model is formulated that formalises the deployment of public policies and multi-level and multi-scale OSH 5.0 strategies within the framework of the Sustainable Development Goals (SDGs) of the United Nations (UN) for Horizon 2030.

The studies about sustainable manufacturing engineering (SME) contain an increasing body of knowledge, motivated by the rising interest in the processes lifecycle sustainability. Its continuous improvement and optimization (including sustainability criteria) has become an emerging necessity. For this reason, new clean technologies and proposals of work methods are required; they have to integrate the ecological and social dimensions at an operational level in the manufacturing processes, maintaining the economic and technical feasibility attained up to this moment. However, a unified framework does not exist to orientate the lines of research in optimization when applied to sustainability. In this sense, the article reviews studies from scientific literature about sustainable machining developed in the last 15 years. The review has been carried out from the triple bottom-line (TBL) perspective, defined by the three general sustainability dimensions (economy, ecology, and equity). It contributes to the literature and current machining engineering knowledge, with its involvement in mitigating the metabolic rift. The results from the review have allowed to characterize the investigation effort, with regard to the optimization of the sustainable machining processes; even though numerous studies exist which optimize machining operations (with the aim to find the trade-off between different environmental and equity factors), in general, the technical and economic feasibilities are still the priority. The patterns defined through the analysis of the publications have established the current development trend; furthermore, as a consequence of the review results, we propose an outline of articulated lines of investigation with the aim to mitigate the metabolic rift through triple bottom-line, necessary so that machining engineering assumes the goal of finding the balance to achieve integral sustainability.

The purpose of this paper is to conceptualize a circular business model based on an Eco-Holonic Architecture, through the integration of circular economy and holonic principles. A conceptual model is developed to manage the complexity of integrating circular economy principles, digital transformation, and tools and frameworks for sustainability into business models. The proposed architecture is multilevel and multiscale in order to achieve the instantiation of the sustainable value chain in any territory. The architecture promotes the incorporation of circular economy and holonic principles into new circular business models. This integrated perspective of business model can support the design and upgrade of the manufacturing companies in their respective industrial sectors. The conceptual model proposed is based on activity theory that considers the interactions between technical and social systems and allows the mitigation of the metabolic rift that exists between natural and social metabolism. This study contributes to the existing literature on circular economy, circular business models and activity theory by considering holonic paradigm concerns, which have not been explored yet. This research also offers a unique holonic architecture of circular business model by considering different levels, relationships, dynamism and contextualization (territory) aspects.

Human Factor strategy and management have been affected by the incorporation of Key Enabling Technologies (KETs) of industry 4.0, whereby operator 4.0 has been configured to address the wide variety of cooperative activities and to support skills that operate in VUCA (volatile, uncertain, complex, and ambiguous) environments under the interaction with ubiquitous interfaces on real and virtual hybrid environments of cyber-physical systems. Current human Competences-Capacities that are supported by the technological enablers could result in a radically disempowered human factor. This means that in the processes of optimization and improvement of manufacturing systems from industry 4.0 to industry 5.0, it would be necessary to establish strategies for the empowerment of the human factor, which constitute symbiotic and co-evolutionary socio-technical systems through talent, sustainability, and innovation. This paper establishes a new framework for the design and development of occupational environments 5.0 for the inclusion of singularized operators 4.0, such as individuals with special capacities and talents. A case study for workers and their inclusion in employment is proposed. This model integrates intelligent and inclusive digital solutions in the current workspaces of organizations under digital transformation.

Manufacturing systems under Industry 4.0, and their transition towards Industry 5.0, take into account the Quintuple Helix innovation model, associated with the sustainable development goals (SDGs) set by the UN and Horizon 2030, in which companies focus on operational efficiency in terms of the use and minimisation of resources for the protection of the environment. In this respect, the implementation of the circular economy model, which requires engineers to acquire appropriate competencies, enabling companies to establish this model at the manufacturing level. Moreover, competence has always been a priority for both the professional and the company. In this sense, connectivism has been called a learning theory for the digital era; this is the reason why a review of the state-of-the-art developments of this paradigm focused on engineering has been carried out. In this sense, the potential of the digital transformation in instruction to formulate an engineering model based on neuro-competences is of great interest, taking the connectivist paradigm as a methodological axis. To this end, a first bibliometric analysis has been carried out to identify the drivers on which to base the design of the neuro-competencies of the instructional engineering environment and the trend towards curriculum development under dual training models. The bibliographical research carried out on the connectivist paradigm has served to identify the trends followed to date in education within the subject area of engineering. These trends have not fully taken into account the leading role of the human factor within the socio-technical cyber-physical systems of sustainable manufacturing (SCSSM). The focus was more on the technology than on the adaptation of the uniqueness of the human factor and the tasks entrusted to him, which entails an additional complexity that needs to be addressed in both academic and professional contexts. In light of the foregoing, an improvement to the acquisition and management of competencies has been proposed to the academic, professional and dual engineering contexts. It is based on the transversal inclusion of the concept of neuro-competence applied to the competence engineering (CE) model, transforming it into the neuro-competence engineering (NCE) model. The foregoing provides a better match between the characteristics of the human factor and the uniqueness of the tasks performed by the engineer, incorporating activity theory (AT), the law of variety required (LVR), the connectivist paradigm and neuroscience as a transversal driver of innovation through fractality. This proposal enables a ubiquitous and sustainable learning model throughout the entire academic and professional life cycle of the engineer, placing it sustainably at the heart of the instructional and professional cyber-physical socio-technical system, thus complying with the SDGs set by the UN and Horizon 2030.