###### Abstract
Failure mode and effects analysis (FMEA) has been extensively used for examining potential failures in products, processes, designs, and services in reference [11], the risk factors such as the occurrence O, severity S, and detection D of each failure mode in the traditional FMEA are treated as fuzzy variables and evaluated by using fuzzy linguistic terms and fuzzy ratings. As a result, fuzzy risk priority numbers (FRPNs) are proposed for the prioritization of failure modes. In terms of the possibilities of failure of bottom events, an algorithm of the intuitionistic fuzzy fault-tree analysis is proposed to calculate the fault interval of system components and to find the most critical system component for managerial decision-making based on some basic definitions [12]. To improve the performance of the FMEA method, some FMEA-based approaches are proposed to integrate the advantages of the Fault Tree Analysis (FTA) and FMEA [13; 14]. In Ref. [15], a fault tree for calculating the reliability of combinatorial logic circuits associated with single and multiple faults was proposed. In order to maximize system reliability, the redundancy strategy, i.e., the active or standby redundancy of each k-out-of-n subsystem in the traditional problem, was determined [16], and the door redundancy was also introduced to improve the reliability of each digital logic gate. In order to improve the reliability and safety of an actuation system, dissimilar redundancy technology has been adopted in modern aircraft design [17]. In reference [18], based on the design optimization under mixed uncertainty, a new kriging model is proposed to solve the design optimization problem of time-varying reliability with flexible constraints. In reference [19], a subregion computing strategy is proposed, and a new learning function is introduced, which can effectively improve the computing efficiency of time-varying reliability. In reference [20], a new coupled Kriging model is proposed to balance computational costs and accurate results. In this paper, an FMEA table for determining the important components of the control system is established. The FMEA and FTA are combined to analyze the reliability of a three-engine simultaneous pouring control circuit system. Based on the established FMEA table, the system is qualitatively and quantitatively analyzed by using FTA. The redundant design of the alarm function can improve the reliability of the control system significantly. However, many redundancies will lead to high cost, complexity, and maintenance difficulties. In order to reasonably evaluate the reliability of an alarm control system with dissimilar redundancies, the control system is divided into several redundant states according to the alarm function, and then Bayesian Networks analysis is applied to obtain the most suitable system redundancy design. The production cost of the solid rocket engine involved is very high. Although the simultaneous pouring of three solid rocket engines greatly improves the production efficiency, the loss is more serious once the pouring fails, so it is more required to ensure particularly high reliability in the production process. In order to ensure this problem, this paper focuses on the reliability of the design of the three-enginesimultaneously pouring control system and the rationality of the redundant design of the designed control system.