Fig. 3 A(t) and R(t) vs. time t under Mode I
Fig. 4 A(t) and R(t) vs. time t under Mode II
5. CONCLUSIONS
A 3-out-of-4:G warm standby system model with nonidentical components is newly developed, where the system is composed of components of type 1 and 2. By using Markov model, the system availability, reliability and failure frequency are obtained. These results are also illustrated by two examples. From the values obtained for system availability and failure frequency, it concludes that Mode I is preferable to Mode II.
The model given in this paper is suitable to be applied to several real systems including power plant, transmission systems.
The method proposed here can be applied to other k-out-of-n:G warm standby systems. The solutions obtained can be reduced to as for the hot and cold standby system by making the dormant failure rate equal to the failure rate of the component in active state or zero. Furthermore, the solutions reduce to as for 3-Out-of-4:G warm standby system with identical components only assuming that components have a common operating-failure rate, an identical dormant failure rate and the same repair rate.
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Appendix
A.1 ProofofLemma 1
Fig. 5 A general state transition diagram
