## 6 Conclusions  
This study conducted reliability analysis and prediction of a new type of prefabricated track structure using the fuzzy FMECA method, and the main conclusions are as follows:  
1. The overall criticality value of the two track structures was calculated using the fuzzy FMECA method. The overall criticality value of the CRTS II slab track structure was 34.7464, while the overall criticality value of the modular assembled track structure with built-in position retention was 33.5803, which indicates that the latter has lower criticality. 2. A reliability prediction model based on the similar product method was established, and the reliability of the modular assembled track structure with built-in position retention was quantitatively estimated. According to the reliability prediction model, the reliability of the modular assembled track structure with built-in position retention is 0.9994, which indicates a high level of reliability. This study provides a scientific basis and relevant recommendations for the design optimization of a new type of prefabricated track structure, which helps to improve their safety and reliability, reduce operation and maintenance costs, and thereby promote the green and low-carbon development of the rail transit industry. The data on the number of faults and the period of the CRTS II slab track structure analyzed in this study are not publicly available due to the data safety policies of the railway operation and maintenance companies. Therefore, we will further conduct scaled and full-scale experiments on the mechanical properties, failure processes, and durability of the CRTS II slab track structure and the new prefabricated track structure to obtain first-hand data on their reliability-related performance. This will help us to further improve the proposed reliability prediction method for the new type of prefabricated track structure in this work. Additionally, applying the reliability prediction method proposed in this study to other types of track structures is also a task that needs to be carried out in the future. Conceptualization, methodology, C.H., Z.S. and Q.W. ; formal analysis, C.H. ; investigation, C.H. and Z.S. ; writing--original draft preparation, C.H. ; writing--review and editing, Z.S. ; supervision, J.W., Z.S. and Q.W. ; project administration, J.W., Z.S., Z.Y. and Q.W. ; funding acquisition, J.W., Q.W., Z.Y. and Z.S. All authors have read and agreed to the published version of the manuscript. This research was funded by the Science and Technology Research and Development Program Project of China Railway Group Limited (grant numbers, Practical Technical Project, No. 2021-Major-02 and Major Special Project, No. 2020-Special-02); The National Natural Science Foundation of China (grant number U1934217); and The China Energy Investment Corporation (grant number SHGF-18-50). Not applicable. The raw data supporting the conclusions in this article will be made available by the authors upon request. Authors [PERSON] and [PERSON] were employed by the company China Railway Group Limited. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declare that this study received funding from Science and Technology Research and Development Program Project of China Railway Group Limited and The China Energy Investment Corporation. The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Number** & **Failure Mode** & **Failure Cause** & **Local Effect** & **Higher-Level Effect** & **Final Effect** & **Fault Detection Method** \\ \hline \multirow{4}{*}{MA7} & \multirow{4}{*}{ \begin{tabular}{c} CA mortar layer \\ layer cracking \\ \end{tabular}  } & \multirow{4}{*}{