Repairable and Non-Repairable Another measure of reliability is availability (probability that the system provides its functions when needed). Maximum Reliability level With Repairs No Repairs Pp…PDi Time System Engineering by J.J. CLGO Gao 6+ - System Engineering by J. J. Gao 6 Maximum Reliability level Reliability With Repairs Time No Repairs  Another measure of reliability is availability (probability that the system provides its functions when needed). Repairable and Non-Repairable