On dynamic information-based life extension

When the level of degradation of a deteriorating system is observed at inspection, a decision can be made either to perform its preventive maintenance (PM) immediately or to postpone it. This type of policy can increase the expected lifetime of a system if executed in an optimal way. The main distinction from the previous works is that for optimal decision, we utilise the information on degradation, which enables to use optimally resources of a system. The case of one possible PM with the deterministic failure threshold is considered in detail. Generalisations to the cases of imperfect PM, several PMs and of a random failure threshold are discussed. The obtained optimal solutions are illustrated by numerical examples.