## 1 Introduction
The precise method, also known as the full probability method [14], involves solving the structural failure probability through the probability density function of precise resistance and load models. The approximation method serves as a substitute for the precise method and includes techniques such as the First-Order Second-Moment (FOSM) central point method [15], the FOSM design point method [16], and the JC method [17]. Probability-based methods rely on probability theory and statistical analysis to assess the likelihood of a system operating successfully under given conditions. These methods typically provide precise quantification of uncertainties and offer comprehensive reliability evaluations. However, they often require a significant amount of historical data or performance parameters from similar systems to establish probability models. However, in the schematic design phase of the new prefabricated track structure, it is difficult to obtain historical data or performance parameters of similar systems, which restricts the application of this precise method. 2. Model-based methods: Model-based methods predict product failure times through deterministic Physics of Failure (PoF) models [18], assuming that uncertainties affecting failure times stem from random variations in model parameters. Product reliability is then estimated using analytical methods or Monte Carlo simulation [19; 20]. The accuracy of these results heavily relies on the precision and completeness of the established model. However, in the schematic design phase of the new prefabricated track structure, due to a lack of sufficient information to establish an accurate model, the application of these methods has also been somewhat limited. Since traditional methods are not available, the main reliability prediction methods used in the schematic design phase are the performance parameter method and the similar product method [21]. The performance parameter method [22] is based on statistical analysis of the relationship between performance parameters and the reliability of a large number of similar systems, deriving empirical formulas and coefficients. The similar product method [23] utilizes the experience and data from existing similar products to predict the reliability of new products. However, for new prefabricated track structures, due to a lack of performance parameters from similar systems, these two methods have certain limitations in predicting their reliability. Therefore, this paper proposes a reliability prediction method for prefabricated track structures based on fuzzy Failure Modes, Effects, and Criticality Analysis (fuzzy FMECA [24]). It integrates the expert survey method, similar product method, fuzzy comprehensive evaluation method, and FMECA [25]. The outline of this paper is as follows: Section 2 introduces the principles of the fuzzy FMECA method. Section 3 uses the fuzzy FMECA method to conduct a comprehensive assessment of fault severity, fault occurrence probability, and fault detection difficulty for the CRTS II slab track structure and the modular assembled track structure with built-in position retention. Consequently, a fault mode hazard assessment model for the new prefabricated track structure is constructed. Section 4 utilizes the similar product method to establish a reliability prediction model for the new prefabricated track structure and carries out reliability prediction for the track structure, verifying the effectiveness of the proposed method.