Quantifying the value of negative inspection outcomes in fatigue maintenance planning: Cost reduction, risk mitigation and reliability growth

Abstract

With the development of sensing, non-destructive evaluation and information technology, benefits of informed structural maintenance decision-making based on systematic decision analysis have been increasingly appreciated and required. This tendency necessitates methods for quantifying the value of information (VoI) provided by condition inspections (or monitoring) and fully utilizing the VoI, i.e., transforming information into improved maintenance decisions that add value. While positive inspection outcomes are often considered as indicators for maintenance actions, implications of negative outcomes on reliability, risk and costs are seldom quantified. The objective of this study is to investigate potential benefits of negative outcomes to maintenance costs, failure risk and reliability from a maintenance planning perspective by developing a probabilistic VoI computational method. A structural maintenance decision-making framework and a VoI computational method are developed, considering uncertainties associated with structural deterioration forecast and inspection outcomes. For the first time, influences of maintenance effect modeling on VoI computation are investigated. The framework and method are illustrated on a marine structure. It is concluded that the VoI from negative outcomes can be attributed to reductions of both maintenance costs and failure risk, especially when high-quality inspection techniques are used and maintenance effects are imperfect.