Roles of Value in the Evaluation and Modeling of Decision Strategies for Pipe Maintenance in Water Distribution Networks

Abstract

Water distribution networks (WDNs) are essential infrastructure systems, providing vital drinking and process water for urban health and economic vitality. The unfolding choices of how and when to maintain these aging networks reflect the values (priorities) invoked by decision makers, and, in turn, these choices determine the value of the service delivered, ranging from adequate water delivery to its alignment with broader environmental, social, and economic objectives. However, the extent to which asset management strategies acknowledge and incorporate diverse values through their priorities, assumptions, and objectives, remains limited both in practice and in modeling research. This paper proposes a computational model to evaluate the performance of long-term pipe maintenance strategies through Monte Carlo simulations of sequential pipe maintenance activities, capturing the probabilistic nature of pipe failure and its impacts across multidimensional performance metrics. Specifically, the model explores how operator priorities affect the choice of different repair and replacement strategies, and the effects of these value profiles across multiple dimensions including both system-level performance and the perception of different stakeholders such as users and service regulators. An illustrative example of a theoretical distribution network shows how valuing pipe replacement over short-term repair can both reduce pipe failure risk and lead to notable improvements in service, environmental, and monetary outcomes. Through an exploration of stakeholder value perception, this study shows that there is potential for alignment between societal objectives such as water losses and energy use, and between global service outcomes and direct maintenance costs for network operators. This study provides a novel exploration of the relationship between value (i.e., preference, priorities, and objectives) across stakeholders, and proposes methodological improvements in pipe maintenance modeling to better reflect the uncertain nature of WDN operation and a generalized and granular approach to pipe maintenance modeling.