Recent Development Techniques on Digital Twins for Manufacturing: State of the Art

Industry 4.0 is the trend of today's industry. It integrates many new technologies such as Big data, Artificial Intelligence, Internet of Things, Cloud Computing, etc. One of the main important areas that are affected by this revolution is the manufacturing sectors. These technologies exist in the industrial field, and they have already served to upgrade the manufacturing process and to put it on the path of digitalization. Therefore, a new concept for smart manufacturing systems that are currently in use, who is the Digital Twin (DT) for manufacturing. It is a virtual reflection of a real element. It can be used to check the flexibility of the manufacturing layout, reproduce complex manufacturing systems and evaluate production efficiency in real time. The DT system allows us to test virtual scenarios, optimize and improve working conditions. It predict also what will happen in the real world. The application of DTs for small and medium-sized enterprises (SMEs) is an important task. It has many advantages to improve the real-time status of machines and products. It ensures also, the continuity between the different areas of industry. The deployment of this concept in the manufacturing sector of an SME, requires the identification of techniques already deployed in the literature. In this paper, the main techniques used in the four layers of DTs, such as the cyber layer, the computing layer, physical layer, and the service layer are reviewed in detail. Their requirements and proposed solutions are also discussed. Another focus, is to provide a framework for the development of DTs for SMEs. On the basis of this framework, we focus on minimizing the costs of digitization. In future works, we aim to implement the proposed framework.