Some Results on Availability of Repairable Component and Repairable Coherent System

Cha, Ji-Hwan

  • Published : 2003.04.01


Availability is an important measure of performance of a repairable component. In this paper, the explicit expression for the availability of a repairable component, which is subject to the policy II(Age Replacement Policy) of Barlow and Hunter (1960), is obtained and the existence of the steady state availability is shown. The steady state availabilities of the model are also obtained for the cases when the mean of the minimal repair time is increasing at a geometric rate or linearly increasing, In order to show the importance and the utility of the obtained result, we also consider an illustrative example of the repairable coherent system whose components are repairable, and the obtained results are applied to derive the steady state availability of the whole system. In this situation, we can see that the condition of the existence of the steady state availability for each component is essential. Some remarks on the optimal replacement policy that maximizes the steady state availability are also given.


Availability;Limiting efficiency;Repairable component;Minimal repair;Replacement


  1. Operations Research v.8 Optimum preventive maintenance policies Barlow, R.E.;Hunter, L.C.
  2. Advances in Applied Probability v.20 A Note on the Optimal Replacement Problem Yeh, L.
  3. System Reliability Theory : Models and Statistical Methods Hoyland, A.;Rausand, M.
  4. Statistical Theory of Reliability and Life Testing, Probability Models Barlow, R.E.;Proschan, F.
  5. On the Use of Stochastic Processes in Modeling Reliability Problems Birolini, A.
  6. Quality and Reliability of Technical Systems Birolini, A.