Periodic inspection optimization for infrastructure systems subject to hidden failures

Abstract

This paper proposes an optimization framework to find the periodic inspection interval over an infinite time horizon for geo-distributed infrastructure systems subject to hidden failures. The unit's failure can only be rectified at periodic inspection, when a failed unit is perfectly repaired. For geo-distributed infrastructure systems, e.g., fire hydrants in a city, water and power supply networks in urban areas, firstly, we cluster the units of a system into groups; then calculate the optimal inspection interval for each group based on the expected cost per cycle; and finally, we determine the best schedule for inspection that not only minimizes the global system inspection and maintenance cost but also meets the labor resource constraints. An integer nonlinear programming formulation together with a heuristics is developed to deal with the inspection schedule. The proposed method is applied to planning periodic inspection of large amounts of fire hydrants in a major U.S. city.