As the systems grow in size and complexity, they become more prone to failures and it becomes essential to ensure their performance by carrying out reliability analysis. Here, the word system connotes any assemblage of functional units and may be used to denote a complete installation or equipment. A system may be quite gigantic such as computer communication networks or it could be as small as an integrated circuitry.
The problem of determining the reliability of systems, whose components can have one or more failure modes, often arises in variety of applications, ranging from telecommunication, transportation, power systems, and mechanical systems to integrated circuits and computer communication systems or large software structure. Therefore, all such systems can naturally be expressed as in the form of a network, arising from the interconnections of various system subdivisions. For instance, a telecommunication or a computer communication network may have vertices representing the physical locations of computers or transmitters/receivers and may have several edges representing the communication links between different sites. Depending on whether vertices or edges work or fail, the network itself can be considered to be either working or failed.
For the applications cited above, continued availability of communication between specified vertices of a network is an important requirement. With the widespread use of and dependence upon such networks, it becomes ...