Prioritizing Water Mains for Inspection and Maintenance Considering System Reliability and Risk

Abstract

This paper presents a method for prioritizing water mains for inspection and maintenance with consideration of municipalities with a lack of data for failure probability assessment. The method employs reliability and risk of a pipeline system to determine the maintenance schedule for each pipe component in the system. A simple Weibull function–based failure prediction model is developed for the pipe components based on a stochastic analysis using Monte Carlo simulation. The failure consequence of the component and the system is determined using an impact factor approach. The system failure of the pipeline network is modeled using fault-tree analysis. The method is demonstrated through application to a simple idealized pipeline network. The study reveals that the choice of thresholds plays an important role in the decision making using this method. A relationship between the risk and the reliability for the system is developed to assist in the experts’ judgment for the selection of the thresholds in a rational manner.