Optimal maintenance policy for a deteriorating system based on the improved δ-shock maintenance model

In the classic δ model, there is only one threshold for maintenance decision. Taking the different levels of failures causing by shocks into account, the interval between successive shocks and different thresholds should be considered when making replacement decision. This paper proposes a replacement policy based on multi-threshold for a deteriorating system which is subject to δ-shock. This approach assumes the failure thresholds will geometrically decrease with the increasing repair times, and. The optimal replacement policy N is determined by using this method, and the average cost in life cycle is minimized. A numerical case study is conducted to validate the related concept and maintenance decision-making model. The results indicate that the proposed method can effectively optimize the maintenance policy and minimize the life-cycle cost.