Unavailability x Unreliability

medini_1052680584

Dear Ansys Team In the literature one finds that Unavailability <= Unreliability, the equality being valid for non-repairable Systems. Well I just tested a FTA with a simple exponential Event with 2.0 FITs and was surprised to find that Unavailability > Unreliability (figure below). Ok, the unreliability values are based on approximation formulas, but I thought they represented an upper bound for the unreliability. Am I overseen something? Thanks for a Feedback! Cheers, Andre Taurines