Digital Twins for Industry 4.0 and Beyond Digital twins (DT) and cyberphysical systems (CPS) are two independently developed yet comparable supporting concepts for smart manufacturing, or xe2x80x9cIndustry 4.0xe2x80x9d in a more popular term. Both of their working principle are based on a close interaction between a physical object and its digital counterpart. Such similarity arouses our curiosity on the association between them. The purpose of this study is to highlight the associations between DT and CPS. With the help of coword analysis, we find that the two terms seldom coappear in the literature. Nevertheless, they link to a similar set of enablingtechnology terms although with different weighting on these terms, implying that they are established on a similar set of technologies. We suggest that topics within a field being developed independent of each other in the early stage is a common phenomenon. The two currently separate literature streams are likely to merge into one in the foreseeable future. We also discuss the future prospect of DT. Other than manufacturing, DT has great potential in applications such as health care and ecommerce.

Concept and Implementation of a CyberPbysical Digital Twin for a SMT Line This paper conducted research on the concept design and implementation of a cyberphysical digital twin system for manufacturing. Based on literature reviews and industry requirements for a cyberphysical digital twin system for manufacturing, this paper proposed a concept design architecture of a cyberphysical digital twin system and its implementation methodology. An application of building a cyberphysical digital twin system for a SurfaceMountedTechnology (SMT) line is illustrated based on the proposed concept and framework. The basic requirements of the proposed cyberphysical digital twin system are divided into three layers, i.e. operations layer, visualization layer, and intelligence layer. Operations layer is about systems modeling of the physical processes and establishing connections with the cyberspace. Visualization layer is related to the collection and displaying of the historical and present data in a visual manner. The intelligence layer is the ability to conduct data analytics and decision makings to identify patterns and bottlenecks, reduce waste, perform predictive maintenance, etc. A proof of the concept prototype is developed based on the proposed cyberphysical digital twin system for a SMT line.