中文摘要：

针对多阶段系统（PMS）的可靠性评估问题,提出了一种基于贝叶斯网络（BN）的可靠性分析模型PMS-BN.PMS-BN模型首先为每个阶段构建各自的BN,其结果命名为phase-BN.为了描述阶段之间的相关性,将所有phase-BN中表示同一部件但属于不同阶段的根节点用有向边连接,并且将所有phase-BN中的叶节点与一个新的表示PMS系统的节点用有向边连接,从而构建出用于刻画PMS系统的BN,称之为PMS-BN.将各个阶段时间离散为m个时间段,利用BN推理算法获得PMS的可靠性参数.通过2个实例详细阐述PMS-BN的建模过程.PMS-BN模型为PMS可靠性分析提供了一种新的策略,能够方便地实施系统可靠度计算、故障诊断、重要度分析等应用.若构建的PMS-BN满足所有非根节点均具有2个父节点,则PMS可靠度的求解过程仅需O（Nm^3）的计算复杂度,其中N为非根节点的个数.

英文摘要：

The paper presents a Bayesian networks （BN） framework for the reliability analysis of phased-mission systems （PMS）, named PMS-BN model. A PMS consists of consecutive and non-overlapping time periods, with system configuration, success criteria, and component behavior varying from phase to phase. Firstly, each phase is represented by a BN framework, named phase-BN. Then, in order to figure the dependences across the phases, all the phase-BN are combined by connecting the root nodes that represent the same component but belong to different phases, and connecting the leaf nodes of phase-BN with a new node representing the whole PMS mission. The new constructed BN is called PMS-BN. In PMS-BN model, each phase time is divided into m segment, and the reliability analysis of PMS is performed by a discrete-time BN model acting on PMS-BN. Two examples are used to expatiate on the proposed approach. The PMS-BN based method provides a new efficient way to analyze the reliability of PMS, especially for those with dynamic phases. Moreover, it is also applicable to system diagnosis and sensitivity analysis. If all the non-root nodes in constructed PMS-BN own not more than 2 father nodes, the computational complexity of evaluating the PMS reliability is O（Nm^3） , where N is the number of non-root nodes.