Performability Analysis of Fault-Tolerant Computer Systems (original) (raw)

Performability is a composite measure for the performance and reliability, which may b e i n terpreted as the cumulative performance over a nite mission time. The computation of its distribution allows the user to ensure that the system will achieve a given performance level. The system is assumed to be modeled as a Markov process with nite state space and a reward rate performance measure is associated with each state. We propose, in this paper, a new algorithm to compute the performability distribution of fault-tolerant computer systems. The main advantage of this new algorithm is its low polynomial computational complexity. Moreover it deals only with non negative n umbers bounded by one. This important property allows us to determine truncation steps and so to improve the execution time of the algorithm.