ABSTRACT
Concerning the evaluation of systems periodically maintained there are only a few papers. Chen (1997) built the evaluation model for both availability and MTBCF of systems under periodic maintenance. Zhao et al. (2004) studied the approximation algorithm for MTBCF, based on the assumption that reliability function of systems periodically maintained could be regarded as exponential distribution with constant failure rate and reasonable error. Nicholls (2005) deduced the accurate algorithm for MTBCF of systems periodically maintained. However, these studies are all based on the assumption that all faults could be repaired successfully within a period of time. The fact is that any fault in complex systems needs to be detected, isolated, and then fixed. Each of the three steps is with a probability of success rather than inevitable event. The probabilities, namely FDR (Fault Detection Rate), FIR (fault isolation rate) and RR (repair rate), are all between 0 and 1 in engineering practice. In this case the above research findings will be not applicable any more.
