Health-and-usage-based maintenance policies for a partially observable deteriorating system

International audienceThe aim of this paper is to discuss the modelling and optimisation of condition-based maintenance policies for systemssubmitted to usage profile changes. The considered system undergoes a monotone deterioration (gamma process) andis impacted by the usage conditions (covariates) via the proportional hazards model. Four different policies are proposedand the optimal maintenance parameters minimising the long-run average maintenance cost are derived. The differentmaintenance policies are numerically compared using Monte Carlo simulations