Network Reliability

Chapter 2

Reliability Evaluation of General SP-Networks

Reliability has become a key factor in the design and operation of modern large, complex, and expensive systems. It is no longer economically feasible to over design system facilities and to introduce excessive redundancy. Since 1950s, the mathematical theory of reliability started receiving a great deal of attention from engineers and mathematician. (Moor & Shannon, 1956), presented their first significant paper on mathematical modules of multi component system. In their paper, they examined that by proper incorporation of redundant units a network of high reliability could be constructed using relatively less reliable components. Subsequently, several papers have been published on the reliability evaluation of redundant and majority voting systems. A large number of techniques exist to improve the system reliability. Some of the important techniques have been:

• Parts improvement method,
• Effective and creative design,
• Use of overrated components,
• Structural redundancy.

The parts improvements technique involve with the improvement of reliability of at least the most critical, if not all, components. However, cost involved in the applications of new production techniques and automation required for this alternative thereof limits its use. Moreover, whatever improvement we may employ, production of a perfect part (100 % reliability) is almost impossible. Besides, this approach becomes unwieldy when one deals with large and ...