To efficiently analyse system reliability, graphical tools such as fault trees and Bayesian networks are widely adopted. In this article, instead of conventional graphical tools, we apply a probabilistic graphical model called the chain event graph (CEG) to represent failure and deteriorating processes of a system. The CEG is derived from an event tree and can flexibly represent the unfolding of the asymmetric processes. We customise a domain-specific intervention on the CEG called the remedial intervention for maintenance. This fixes the root causes of a failure and returns the status of the system to as good as new: a novel type of intervention designed specifically for reliability applications. The semantics of the CEG are expressive enough to capture the necessary intervention calculus. Furthermore through the bespoke causal algebras the CEG provides a transparent framework to guide and express the rationale behind predictive inferences about the effects of various types of the remedial intervention. A back-door theorem is adapted to apply to these interventions to help discover when causal effects can be identified from a partially observed system.
翻译:为了有效分析系统的可靠性,广泛采用了断层树和巴耶斯网络等图形工具。在本条中,我们使用一种称为链状事件图(CEG)的概率图形模型,而不是传统的图形工具,以代表系统的失败和恶化过程。CEG来自事件树,可以灵活地代表不对称过程的演进。我们定制了CEG的针对特定域的干预措施,称为维护的补救干预措施。这纠正了失败的根源,使系统状态恢复到与新的一样好:一种专门为可靠性应用而设计的新型干预措施。CEG的语义表达得足以捕捉到必要的干预计算。此外,CEG通过直观的因果代数提供了一个透明框架,用以指导和表达预测各种补救干预措施的影响背后的理由。一个后门的标词被调整适用于这些干预措施,以便帮助发现从部分观察的系统中可以识别的因果关系。