ABSTRACT
A hybrid maintenance policy that combines inspection in early life with opportunistic replacement in later life is developed for a one-component system with a heterogeneous lifetime. Inspections and replacements use opportunities that arise periodically, for example due to visits of a maintenance vessel to a turbine in an offshore windfarm. Components may be weak or strong, and the inspection phase of the policy operates like a burn-in period. Inspections are modelled using the delay time concept. The policy mimics reality whereby new systems are carefully maintained and older systems are replaced at events determined by operational constraints. We determine the cost-rate and reliability of the hybrid policy. Using a numerical example we show that the inspection phase offers benefits when the delay time is sufficiently large and/or early failure is a significant possibility. The policy would be relatively easy to implement in practice.
