Reliability assessment of water supply systems

When considering the theory of reliability in the design, operation and maintenance of water supply systems, the assessment of system reliability, in addition to the establishment of reliability criteria, must also be made. Reliability assessment is based on the elaboration of a reliability block diagram of the system, which represents the connections between its elements to determine the dependence of a system's failure on the failures of its elements. There are general formulae given for establishing the reliability of a system with series, series-parallel or series-threshold, parallel-series or threshold-series structures and special methods are applied for establishing the reliability of systems with complex structures. An example of a reliability model of a water network transit mains is presented.