The integration of digital twin (DT) technology into circular economy (CE) frameworks has emerged as a critical pathway for achieving sustainable and intelligent manufacturing under the Industry 4.0 paradigm. This study addresses the lack of structured guidance for DT adoption in CE strategies by proposing two interrelated frameworks: the Sustainable Digital Twin Maturity Path (SDT-MP) and the Digital Twin Nexus. The SDT-MP outlines progressive stages of DT deployment—from data acquisition and real-time monitoring to AI-enabled decision-making—aligned with CE principles and Industry 4.0 capabilities. The DT Nexus complements this maturity model by structuring the integration of enabling technologies such as AI, IoT, and edge/cloud computing to support closed-loop control, resource optimization, and predictive analytics. Through a mixed-methods approach combining literature analysis and real-world case validation, this research demonstrates how DTs can facilitate lifecycle intelligence, enhance operational efficiency, and drive sustainable transformation in manufacturing. The proposed frameworks offer a scalable roadmap for intelligent circular systems, addressing implementation challenges while supporting Sustainable Development Goal 9 (Industry, Innovation, and Infrastructure) by promoting digital infrastructure, innovation-driven manufacturing, and environmentally responsible industrial growth. This study contributes to the advancement of digital infrastructure and sustainable circular supply chains in the context of smart, connected industrial ecosystems.
Sajadieh et al. (Wed,) studied this question.