Recently in our country, there has been a local inequality phenomenon of water supply. This happens because when designing and constructing the pipe network, the amount of demand and supply, and the reliability of the pipe network wasn`t considered. Therefore in this study, we are going to examine the reliability of pipe network and we are trying to develop a new reliability computation considering the unreliability of demand of each node. For the new reliability computation method, two factors of the reliability are used. One is the "Connectivity" which decides the connection of the pipe network, and the other is "Expected Shortage" which decides the amount of demand by the hydraulic inspection. Also, for a faster and easier calculation of the two factors, the Monte Carlo Simulation was used.
