Abstract: The paper deals with systems suffered from gradual deterioration. To avoid functional failures and disastrous consequences, such systems should be monitored and preventively maintained. And to promote the maintenance effectiveness, an unequal time-interval maintenance policy was brought forward to substitute fixedinterval preventive maintenance strategy. At the same time, preventive and corrective maintenance actions are both assumed to be imperfect, and their impact on the system is expressed by the increment of failure rate. The case study shown that the unequal time-interval maintenance policy proposed in the paper is of help to promote the availability of the system.

Key words: Monte Carlo simulation | unequal time-interval| imperfect maintenance

摘要： The paper deals with systems suffered from gradual deterioration. To avoid functional failures and disastrous consequences, such systems should be monitored and preventively maintained. And to promote the maintenance effectiveness, an unequal time-interval maintenance policy was brought forward to substitute fixedinterval preventive maintenance strategy. At the same time, preventive and corrective maintenance actions are both assumed to be imperfect, and their impact on the system is expressed by the increment of failure rate. The case study shown that the unequal time-interval maintenance policy proposed in the paper is of help to promote the availability of the system.

关键词: Monte Carlo simulation | unequal time-interval| imperfect maintenance