FROM STATIC CAD TO DYNAMIC DIGITAL TWINS: A SYSTEMATIC REVIEW OF DATA-EXCHANGE FRAMEWORKS IN INDUSTRY 4.0 MANUFACTURING

Industry 4.0 is transforming Computer-Aided Design (CAD) from a largely static engineering representation into a potential source of structured information for connected manufacturing systems. CAD is used to capture the geometry, topology and tolerances of a design along with materials and design intent, but it is not itself the changing operational condition of a physical asset. Digital Twins overcome this limitation by connecting digital models with physical products, machines or processes via sensing, industrial communication, analytics and feedback. The presented Systematic Literature Review follows the PRISMA 2020 guidelines and synthesizes the exchange formats used to facilitate the transition from static CAD to dynamic Digital Twin in manufacturing. It takes a look at file-based and neutral product-model standards, application programming interfaces, industrial communication protocols, semantic models, Asset Administration Shells, Product Lifecycle Management systems, Manufacturing Execution Systems and digital-thread architectures. An eight-dimensional taxonomy of the literature is developed, based on exchange mechanism, interoperability level, Digital Twin maturity, lifecycle phase, model fidelity, synchronisation frequency, interface architecture and digital/physical creation sequence. The synthesis demonstrates that geometric translation alone is not enough for a functional Digital Twin Engineering meaning, Asset identity, Asset versions, Process context, Data quality, Synchronisation and Cyber security are also essential for a successful integration. Proprietary formats, semantic heterogeneity, legacy equipment, lack of lifecycle traceability, skills gaps and limited ability to validate in the operational environment are persistent challenges. In developing industrial economies, evidence from Southern Africa indicates that enabling technologies exist but interconnection is often weak, exacerbated by these challenges. The review hence suggests a multi-layered reference architecture consisting of CAD and PLM to store the design intent, interoperability mechanisms to enable the exchange of contextualized data, industrial systems to feed the operational data and the Digital Twin to sustain monitoring, prediction, optimization and engineering decision making.