## 1 Introduction
Those three methods are: (i) Offline, a dedicated virtual environment (usually each robot brand has their own) for programming each aspect of the robotic cell for later deployment through the network to the physical robot; (ii) Online, which is being adapted by means of sensor information, usually being twinned in the dedicated virtual environment (e.g., ROS (Robot Operation System), and is able to directly affect the pre-programmed path and routine of the robotic systems; (iii) Manual, which is robot programming by the usage of a flex pendant, but with the introduction of VR/AR interfaces, it also uses a twin for manipulation near the virtual robot remotely [8]. As can be observed, combinations of those methods exploit the virtual twin of the robotic cell and are widely used across the various industrial sectors. Moreover, Digital Twin is used as a validation tool for HRC (Human-Robot Collaboration) safety standards, to evaluate the safety level of the system first, for example, using VR human avatars, before experiments with real operators in the actual system. In this study, it is possible to visually check the converted 3D model in a virtual environment for product designers, purchasing teams, and laboratory staff of small and medium-sized enterprises that lack manpower and capital as well as large enterprises. Then, one develops a VR/AR-based product inspection environment that enables collaboration, which is the main goal in terms of the CAD data conversion process of the CPS-based VR/AR system. In addition, the research is focused on establishing a cooperative relationship between each system entity that observes, calculates, and manipulates physical phenomena through CPS. The smart factory market is expanding with the development of technology following the fourth industrial revolution. Advancements in smart factories include factory automation, and various mechanical devices perform the process automatically. With the introduction of smart factories, field workers mainly carry out inspections and fault repairs, and field workers need a lot of prior learning to check and repair various mechanical devices. In the manufacturing industry, skilled workers are aging, and it is difficult to properly train unskilled workers due to the increased complexity of manufacturing facilities. Collaboration ideas are also emerging as the need for untact emerges due to the COVID-19 pandemic. In the manufacturing industry, collaborations often use AR and VR technologies, and as a result, related jobs are increasing worldwide. To cope with the changing era of the fourth industrial revolution's innovative management paradigm, it is necessary to accelerate the construction of smart factories in the manufacturing industry, and the 3D design and manufacturing content sectors show high potential for growth. It is also necessary to introduce a standardized CPS communication platform technology to facilitate the construction of smart factories in the manufacturing industry [9]. OPC UA (Open Platform Communications Unified Architecture) has become an integral part of the construction of CPS communication platforms that must have an independent and standardized communication method between different species. OPC UA technology is considered to be important and valuable for data exchange and standardized data exchange for various industrial applications such as ERP (Enterprise Resource Planning)/MES (Manufacturing Execution System)/PDM (Product Data Management). To increase the reliability of BigData, OPC UA, a device-friendly communication, high value-added is created with the high reliability of simulation. OPC UA has real-time functionality in Ethernet environments with TSN (Time Sensitive Network), thus making it suitable for the high performance needs of the VR/AR network, and OPC UA-based CPS connects closed networks as standard networks in response to numerous industrial protocols to integrate OT and IT.