Cost-benefit criteria in optimizing maintenance strategies

The life extension of existing deteriorating structures requires maintenance interventions which allow partial or complete rehabilitation. However, such maintenance interventions have to be economically reasonable, that is, maintenance expenditures have to be outweighed by expected future benefits. For this purpose, cost-benefit criteria are developed herein, which not only allow to specify optimal sequences of maintenance times and rehabilitation efforts, but which also allow to determine optimal lifetimes and acceptable failure rates. Numerical examples show, that deferring decisions with respect to maintenance not only results, in general, in higher losses, but also in no longer acceptable, that is, potentially hazardous structures.