Dependability modeling and evaluation of recovery block systems

The paper presents performance modeling and evaluation of recovery block systems. In order to produce a dependability model for a complete fault tolerant system we consider the interaction between the faults in the alternatives and the faults in the acceptance test. The study is based on finite state continuous time Markov model, and unlike previous works, we carry out the analysis in the time domain. The undetected and total failure probabilities (safety and reliability), as well as the average recovery block execution time expressions are obtained. Derived mathematical relations between failure probabilities (i.e. reliability and safety) and modeling parameters enable us to gain a great deal of quantitative results.