"Long-term Deterioration and Investment Modeling of Water Distribution " by Bethany M. Dorian

Date of Award

3-2024

Document Type

Thesis

Degree Name

Master of Science in Engineering Management

Department

Department of Systems Engineering and Management

First Advisor

Takagi Iguchi, PhD

Abstract

The United States Air Force (USAF) and municipal utilities rely on asset management processes to maximize utility of infrastructure assets while decreasing maintenance and repair costs. One of the core tenants of asset management is assessing the condition of the asset, which for water distribution pipes is challenging and costly to obtain. As a result, asset managers often rely upon pipe deterioration modeling using existing data, filling in the gaps when assessments are not available. This thesis uses USAF water distribution network data to develop a series of time-homogenous Markov chain probability models based on two sampling methods and four covariates: diameter, material, both material and diameter, and neither material nor diameter. An estimated Markov chain is obtained via a least square approach and solved via non-linear optimization, and is then used to project the condition of the portfolio. Investment levels are assessed for their impact on condition with pipe replacements costs from RSMeans. The results found that an annual investment of 0.25% of the total plant replacement value of all assets would improve the condition of the network, gradually replacing all pipes in the worst condition. This model can also inform asset management objectives while ensuring quality network performance.

AFIT Designator

AFIT-ENV-MS-24-M-117

Comments

A 12-month embargo was observed for posting this work on AFIT Scholar.

Distribution Statement A, Approved for Public Release. PA case number on file.

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