## 2 Related Work
### Existing Research
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Author** & **Year** &
\begin{tabular}{c} **Technique/** \\ **Environments** \\ \end{tabular} & **Key Contributions** & **Limitation** \\ \hline \multirow{3}{*}{**[PERSON] et al. [17]**} & \multirow{3}{*}{2019} & \multirow{3}{*}{Blockchain; Smart Manufacturing} & Blockchain solves the problem of multi-party trust and provides a secure transmission and storage mechanism to improve SM’s transaction efficiency. & No simulation to prove the result. \\ \hline \multirow{3}{*}{**[PERSON] et al. [18]**} & \multirow{3}{*}{2020} & \multirow{3}{*}{Blockchain, Digital Twin} & An optimal matching system is proposed to protect transaction records in DT using Blockchain. The Blockchain in the system uses an improved consensus algorithm to ensure users’ privacy and service providers’ credibility. & No simulation to prove the result. \\ \hline \multirow{3}{*}{**[PERSON] et al.**} & \multirow{3}{*}{2020} & \multirow{3}{*}{Blockchain, Digital Twin} & A collaborative mechanism of SM services on an industrial Internet platform based on DT-Blockchain is proposed. This work also points out challenges in service management in SM. & No simulation to prove the result. \\ \hline \multirow{3}{*}{**[PERSON] et al. [20]**} & \multirow{3}{*}{2020} & \multirow{3}{*}{Blockchain; Smart Manufacturing} & This paper subdivides the possible security problems in SM and summarizes the indicators of the application of Blockchain in SM. & No proposed idea. \\ \hline \multirow{3}{*}{**[PERSON] et al. [21]**} & \multirow{3}{*}{2020} & Digital Twin; Smart Manufacturing & DT-based workshop scheduling is implemented with high scheduling accuracy and real-time data mapping. The validity of their system in SM is verified. & Lack of processing of real-time data. \\ \hline \multirow{3}{*}{**[PERSON] et al. [22]**} & \multirow{3}{*}{2021} & Blockchain, Machine Learning. Smart Manufacturing & Combine Blockchain and machine learning to improve data quality and device reliability in SM. & Performance in complex network environments is not considered. \\ \hline \multirow{3}{*}{**[PERSON] et al. [23]**} & \multirow{3}{*}{2021} & Blockchain, & An automotive manufacturing case integrating machine learning and Blockchain is proposed to increase production and meet automation requirements, which is expected to be deployed in smart cities. & No proposed idea. \\ \hline \multirow{3}{*}{**[PERSON] et al. [24]**} & \multirow{3}{*}{2021} & Digital Twin. Smart Manufacturing & The DT association technology that can be applied in SM is summarized, and the model of DT development is systematically summarized based on consistency. & No proposed idea. \\ \hline \multirow{3}{*}{**[PERSON] et al. [26]**} & \multirow{3}{*}{2021} & Blockchain, Digital Twin & A reliable and efficient decentralized digital twin framework for industrial networks is proposed, which can be adapted to work in many industries using the physical infrastructure. & Fine-grained service details further complicate the proposal approach. \\ \hline \multirow{3}{*}{**Our work**} & \multirow{3}{*}{2022} & Digital Twin, Blockchain. & Provides a heuristic DT data scheduling framework that considers efficiency and security. & Malicious behavior within DT may occur. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._[PERSON] et al. [24] proposed that the current manufacturing process has an increasingly strong demand for the rapid allocation of production resources and adaptation to the environment. To adapt to this demand, the deployment of DT is imminent. They also summarize the technical challenges to be overcome in DT deployment, including integration of different domains, generation of fidelity models, and communication of heterogeneous data. It emphasizes that DT and IoT, cloud computing, and AI have an excellent expected integration effect, laying a foundation for our research. [PERSON] et al. [25] summarized the definition of DT in SM, sorted out the standardized DT modeling process in detail, and summarized the SM scenarios in which DT can be deployed.