An improved AGREE method with reliability mathematical model for complex system importance degree computation

During the system design process, there are numerous factors that should be taken into account to incorporate reliability requirements into subsystems. The AGREE method is one of the most applicable methods to achieve system reliability allocation. However, when applied to some complex systems, this traditional method may become invalid. Firstly, the allocation results may become distorted and a computation method for the degree of importance is not proposed. Generally, this method can be only used for systems in series or parallel. To address these issues, the traditional AGREE allocation method needs to be modified. This paper proposes a novel degree computational method for complex system allocation whereby the traditional AGREE method is integrated with a mathematical model of system reliability. A framework for the new reliability allocation method is described. In practice, this novel method is used for the reliability allocation of a ship power system. A sensitivity analysis was conducted across several design requirements. The allocation results were verified, demonstrating the use in practical applications.