Notice of RetractionHybrid preventive maintenance and inspection scheduling for a multi-unit series system

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

A hybrid maintenance and inspection model is proposed for a series system with n+1 units subjected to two different failure patterns, which include deterioration and random shocks. The stationary laws for the failure process of the system are derived in order to evaluate the long-run average running cost on an infinite span generated by the proposed opportunistic policy. A periodic inspection is employed to monitor the states of system, upon which one needs to decide whether to perform maintenance. The preventive and opportunistic maintenance thresholds for degradation process & inspection interval are the decision variables of the proposed model. The behavior of the proposed maintenance policy is illustrated through numerical experiments. A comparison between the proposed approach and the juxtaposed single-unit policy is given, which demonstrates the advantages of the proposed opportunistic maintenance policy in reducing the maintenance cost significantly.