Thanks serfty
Can I take it when expertflyer shows the availability of 'U' class that takes into account the award and upgrade availabilities rolled into one.
Sort of. There is a difference between International and Domestic. For domestic, U availability can be used to either redeem directly for a Business Class award, or to request an immediately confirmed upgrade, so this is the way it mostly works for domestic bookings. I have no idea what is done with respect to on-departure upgrades, as I don't know if the buckets get changed before or after the seat is assigned (at around T-10).
International is totally different. If U is available, then you could redeem an Award booking in Business. Upgrades are not confirmed, but only queued, and then processed sometime before departure. If the upgrade is confirmed, the segment is listed as U class, but this says nothing about whether that was made available or visible in any GDS before it was assigned to the booking in question.
It may be a safe supposition that if U seats remained unclaimed at the 24 hour mark, they will be used to fulfil requested upgrades, but who knows how yield management treats the situation. Other seats may be made available (theoretically increasing U from 0), or not. I have had success obtaining 2 upgrades (into U), when availablity was J3D0I0 for the whole week leading up to departure.
J9D9I9 and even U9 as well at 24 hours may not bode well for upgrades depending on a whole range of external factors. If there are no revenue J class pax, then QF may decide the optimum yield management approach is to leave the cabin empty and save on the crewing and other costs, rather than providing any upgrades (unless of course the Y cabin is oversold). The permutations are large, and only the insiders at QF yield management (and I am definitely not) would know them.
Anecdotal experience is the best guide, but should only be treated as a guide, as a liberal amount of luck is also required.
