Could spend an age picking that diagram apart. If we were to take the world famous Harrier and it’s servicability that was the envy of all other types...if you totted up the total in the U.K. - including those with BAE, ETPS, FJTS, in upgrade to the big donk etc I think you got into the mid 70s. About half that amount were fragged to Cottesmore. So that would be a AVA of 50%, wouldn’t it? So 50% AVA would seem quite good.
How do you measure time for the other two metrics? Days? Hours? If it flies once is that a day serviceable? If it does the morning go and falls over in the afternoon does that mean a bad day or a 50% day? If a squadron with 12 jets managed a 4 turn 4 turn 2 in the day and a night wave of 4 - (quite reasonable) what would that mean for ‘time serviceable’?