This tool calculates both mean time between failures and mean time to repair, and the availability they produce together.
Calculate Mean Time Between Failures and Mean Time To Repair from your operating hours and failure history. See how they combine to determine inherent availability, and model what improving one or the other does to uptime.
One tells you how often an asset fails, the other how fast you recover. Availability depends on both.
Inherent availability equals MTBF divided by the sum of MTBF and MTTR.
It depends on your constraint. If failures are rare but repairs are slow, MTTR is your lever. If failures are frequent, work on MTBF.