An Inspection-Maintenance model for a degraded system subject to δ-random shocks

There are many degraded systems existed in the complex system such as the aircraft, and it is very significant to plan appropriate Inspection-Maintenance activities to decrease the failure probability and maintenance cost rate. So an inspection policy for a degraded system with two independent competing failure processes is proposed firstly. Then a degradation path and δ - random shocks are adopted and analyzed. Furthermore, the inspection interval (I), threshold coefficient (k) and PM critical threshold value for degradation (L) are chosen as optimized variables, and an unequal Inspection-Maintenance optimal model is developed to minimize the maintenance cost rate, and the solution method to model is given. Finally, a numerical example is illustrated for case study, and the result proves the model validity and effective.