An Unscheduled Maintenance System.

The ultimate output of any system is the performance of some intended function. If the system is effective, it carries out this function well. If it is not effective, it carries out this function well. If it is not effective, attention must be directed to those system attributes which are deficient. In order to study those attributes which are deficient sound maintenance records are a necessity. The system developed at the Air Force Weapons Laboratory provides detailed records against each piece of equipment in the dual CDC 6600 computer system. The logging forms used are concise and contain all the needed data. The program, MNT, is written in FORTRAN for the 6600. The data collected form the basis for the reliability analysis described in Section IV. The measure of an equipments reliability is the frequency at which failures occur in time. Reliability theory and practice differentiate among three types of failures initial, random, and wearout for two main reasons. First, each of these types of failures follows a specific statistical distribution and therefore requires a different mathematical treatment. Second, different methods must be used for their elimination. The Air Force Weapons Laboratory computer center is dealing with the random failure region and the statistical theory underlying the data analysis is described in Section IV.