ABSTRACT

The limiting availability for a device is the limit of the point availability function. The analysis of availability can become quite intricate, so it is usually performed relative to a very carefully defined statement of the assumed operating and repair scenario. This is because very minor differences in operation plan and particularly in the assumed failure and repair distributions may have quite pronounced effect on the identity of the appropriate model and its solution. Very few availability results have been developed for the cases in which repair does not imply renewal. A. Birolini has used Markov chains and Markov processes to represent device and system-level behaviors and have used the Markov models to obtain availability or cost measures. The core idea for the Markov models is to represent system status. For some of the more complicated cases, the use of the Markov process model is easier than the direct analysis of the renewal process model.