Cost-benefit optimization and risk acceptability for existing, aging but maintained structures

The theory for setting up suitable objective functions is extended to existing structures which can have a different distribution of the time to first failure than all other failure time distributions if systematic reconstruction is chosen in a model based on renewal theory. If components are aging, inspection and maintenance should be performed requiring appropriate modifications. These modifications not only affect the objective function but also the risk function and the failure rate that usually is increasing. Therefore, special consideration is given to the question of risk acceptability where the transient behavior of the failure rate is of interest.