Availability, Reliability, and Maintainability

Abstract Availability is the probability that a system will operate satisfactorily at any point in time, where time includes not only operating life but also active repair time and administrative and logistic time. This chapter deals primarily with reliability. The reader should consult the following: MIL‐HDBK‐472, Maintainability Prediction for methods to predict MTTR MIL‐STD‐471A, Maintainability Verification/Demonstration/Evaluation . The information in this chapter consists of abstracts from the Appendices to MIL‐HDBK‐217C, Reliability Prediction of Electronic Equipment [Ref. 3 ]. Reliability, as discussed in this chapter, deals only with reliability of equipment and entire systems. It does not deal with propagation reliability (preferred term is “time availability“) where there might be downtime due to fading or other propagation impairment. Here the theme is equipment failure or degradation. Obviously, such a failure or degradation will affect the system to which the equipment is a functional part.