Reliability Allocation Based on Importance Measures

How to properly assign the reliability to the components is a key process for a system design, especially for a system in nuclear installations with high reliability requirements. Previously the reliability allocation process for such a system with high availability requirements is done based on the failure mode effects and criticality analysis (FMECA) and fault tree analysis (FTA). The results from FMECA are just qualitative. The analysis based on FTA needs to be iterative and probably can only get the sub optimal solution. In this paper, a theoretical model is proposed based on importance measures (IMs) and it is competent to allocate the reliability indices to its different composed components quantitatively. Moreover, the optimal assignment result can be obtained directly without any iterative processes. Thus, the proposed method is theoretically valuable and is also much beneficial to the design of the related complex systems and devices of the nuclear power plants. The control cabinet design, as a typical example, is introduced and the proposed method is demonstrated to be effective.