QUANTITATIVE APPROACHES TO RELIABILITY ASSESSMENT IN PIPE NETWORKS.

Two quantitative approaches to the incorporation of reliability measures in the least-cost design of looped water distribution networks are developed and assessed. Both approaches begin by obtaining an 'optimal' layout design through linear programming. The first approach addresses the probability of isolating a node through simultaneous failure of all links connected directly to that node. The second approach attempts to recognize redundancy by minimizing the deviations in the reliabilities of all pipes connected to each node within the network. In both cases, the probability of failure of individual links is modeled using the Poisson probability distribution.