Novel Approach in Pipe Condition Scoring

A major challenge in sewer and water pipe infrastructure management is determining structural condition scores for pipe assets. The methodology used to determine the condition of pipes should be relevant, repeatable, and validated. Additionally, to be appropriate for use in risk-analysis models, the scale selected to represent the structural condition should be linear. The methodology developed in this paper enables previously developed pipe statistical failure models to be translated into a mean time to failure (MTF) for individual pipes. By using the economic concept of discounting, the MTF is then used to score the structural condition of the pipe, providing an appropriate structural condition score for use in risk-based asset management models. This methodology for determining the structural condition score has several advantages over previously developed models: the results can be easily interpreted and validated, and the resulting scale is linear. Additionally, the system can be implemented for pipes with differing levels of available data, such as for pipes with and without inspection results.