Interval availability distribution computation

Interval availability is a dependability measure defined by the fraction of time during which a system is in operation over a finite observation period. The computation of its distribution allows the user to ensure that the probability that a system will achieve a given availability level is high enough. As usual, the system is assumed to be modeled by a finite Markov process. The authors propose two new algorithms to compute this measure and compare them with respect of the input parameters of the model, both through the storage requirement and the execution time points of view. It is shown that one of them is an improvement of a well-known one. Both algorithms are based on the uniformization technique.