Probabilistic assessment of availability from system performance data

This paper presents a method of calculating system availability and reliability probability distributions using permutations of inseparable system failure and restore data sets. Such data sets usually come from system history, as reflected in a performance measurement such as daily production. A direct relationship is maintained between any failure and its consequence; that is, time-between-failure (TBF) and time-to-restore (TTR) are an inseparable set. Furthermore, TTR need not be single-valued but may take the form of another data set to accommodate system degradation and dependent failures