Markov Repairable Systems with Multi-Working Levels：Some New Reliability Indices

States with same working level were regarded as one class, and whole state space was divided into several working levels. The model of Markov repairable system with multi-working levels was constructed, and the reliability about the system was also studied. In terms of ion channel modeling theory, Markov process theory and matrix partition method, some new reliability indices for the system were presented, i.e., point availability, interval availability, point-interval-mixed availability and others. A numerical example was taken to simulate the contentions presented in the paper, and the simulation results show that these new indexes can be applied to Markov repairable system model.