Extended Optimal Replacement Policy Based on Cumulative Damage for a Two-Unit System Subject to Shocks  
Author Shey-Huei Sheu
Co-Author(s) Tzu-Hsin Liu; Zhe-George Zhang; Hsin-Nan Tsai
Abstract This article examines the extended optimal replacement policy for a system consisting of two major units (A and B), which is subject to two types of shocks that arrive according to a non-homogeneous Poisson process. A type I shock causes a unit A minor failure and is removed by a minimal repair. On the other hand, a type II shock will cause a complete system failure and is rectified by a corrective replacement. The probability of a type II shock is permitted to depend on the number of shocks suffered since the last replacement. Each unit A minor failure results in an amount of damage to unit B. These damages to unit B can be accumulated to a specified level of the complete system failure. Furthermore, unit B with a cumulative damage of level z may become minor failed with probability ϖ(Z) at each unit A minor failure and is removed by a minimal repair. This paper proposes a more general replacement policy where the system is replaced at age T, or the Nth type I shock, or the first type II shock, or when the total damage to unit B exceeds a pre-determined level K, whichever occurs first.
Keywords Optimal maintenance; minimal repair; Cumulative damage model; Shock model; Replacement policy
    Article #:  23-160
Proceedings of the 23rd ISSAT International Conference on Reliability and Quality in Design
August 3-5, 2017 - Chicago, Illinois, U.S.A.