Imperfect maintenance decision for a deteriorating system based on shock model

With respect to the deteriorating system whose failure was induced by external shock,this paper proposed a newδ-shock failure model and studied an imperfect maintenance method based on this shock model with the replacement policy N.Firstly,it presented a newδ-shock failure model on the basis ofδ-shock model by extending failure states,and then established an imperfect maintenance decision model for this system,which achieved the minimum the long-run average cost per unit time conditional on the constraint of availability;finally,it provides a numerical example to demonstrate the usefulness of the proposed method,and also studies the sensitivities for the policy N with respect to parameters.