A Survey of Network Reliability Modeling and Calculations

A brief survey of the subject of network reliability is presented. Network reliability is the study of network performance when components of the network are subject to failures. The problem can be divided into two main parts: the modeling of component failures and the corresponding reliability calculations. In the modeling of component failures, the assumption that component failures are statistically independent is often made to simplify the problem. But this assumption is unrealistic in most real-world situations. In this survey, special attention is given to recent developments in modeling statistically dependent failures of network components. For reliability calculations, only analytical techniques are considered, and simulations are excluded. A brief classification of existing techniques is given. Since most network reliability problems are NP-hard, exact techniques to calculate network reliability can only handle problems of limited sizes, and therefore approximate techniques are of practical importance. Both exact and approximate techniques are covered in this survey.