Discussion of compensating faults in modelling of NMR system reliability

To obtain realistic estimates of reliability of systems with N-tuple Modular Redundancy (NMR) the effect of compensation of logical faults should be considered. Throughout the analyses made up to date, different models of compensating faults have been considered, producing results that are rather impractical and yield very complex mathematical formulas for reliability indices. In this paper a general model is presented that combines the ideas most commonly applied. As a main result some useful estimates are given of upper and lower bounds of reliability indices of NMR systems with compensating faults.