可靠性分配理论在系统安全目标实现中的应用

在系统安全理论中,确定各基本事件的可靠度以实现所给定的系统安全目标值问题一直没有得到很好解决。笔者将可靠性分配理论与故障树分析方法相结合,提出了2个层次可靠度分配法:最小割集之间采取可靠度再分配法,对构成最小割集的各个基本事件之间采取等分配法。从而建立系统中各单元可靠度再分配量化模型。为便于应用,通过实例,详述系统各单元可靠性分配的计算过程。研究表明,运用该模型可准确、简便地计算出各单元的可靠度,使系统在给定的目标值条件下达到系统的安全性优化。

Application of Reliability Distribution Theory to the Realization of System Safety Target

In system safety theory, the problem to realize the given value of system safety target by deciding the reliability of each basic event has not been well solved till now. Aiming at this point, a two-layer reliability distribution method is put forth by combining reliability distribution theory with fault tree analysis (FTA). In the first layer calculation, the reliability is redistributed among the least cut sets, and then the reliability is equivalently distributed among the basic events in the second layer calculation. Thus, a quantitative model for calculating the reliability of each component in system is set up. Finally, this method is demonstrated by an example. It shows that this model can conveniently and precisely calculate the reliability of each unit in a system and fulfill the optimization of system safety under the condition of a given target.