Optimal Maintenance‐Related Decision Making for Deteriorating Water Distribution Systems: 2. Multilevel Decomposition Approach

A water distribution system often consists of a large number of components. However, funds are, in general, not available to completely update/upgrade the deteriorating water distribution system's components. Limited funds have to be optimally distributed among the system's components on the basis of the contribution of each component to the overall system's availability. The large dimension and high degree of nonlinearity of models of deteriorating large‐scale water distribution networks make the maintenance‐related problem difficult to handle as a whole. In this paper a multilevel approach is proposed for water distribution systems that maximizes the availability of the overall system under a given cost constraint. This decomposition method tackles a large‐scale nonlinear programming problem by solving a set of linear programming problems with a smaller dimension iteratively, thus greatly reducing a large‐scale system's complexity.