ESTIMATION OF FAILURE INTENSITY AND MAINTENANCE EFFECT UNDER TWO DIFFERENT ENVIRONMENTS

초록

The maintenance effect is a peculiar factor of repairable systems. Malik (1979) and Brown, Mahoney & Sivazlian (1983) proposed general approaches for the maintenance effects, where each maintenance reduces the age of the unit with respect to the rate of occurrences of failures. An important problem in failure data analysis has been that all parts of data have not always been collected under similar conditions. We consider an estimation problem of repairable systems under two different environments and Malik’s proportional age reduction model. Failure intensities depending on environmental conditions and maintenance effect are estimated by the method of maximum likelihood. Simulation results are presented to illustrate the accuracy and the properties of the proposed estimation method.