Originally Posted by flyastrojets
According to the membership guide, they will automatically try to process your upgrade up to 3 hours prior to departure.
At that 3 hour mark, upgrades are processed at the airport. IF some "X" inventory happens to open up during that timeframe between 3 hours and departure time (and X is what the 500 miler e upgrades are processed in), and a gold guy just happens to walk up to the counter and ask if he can get an upgrade confirmed, the gold will get the upgrade no matter how many EXP's, PLT's, and GLD's that previously requested upgrades were in the automatic queue.
I appologize for not being able to remember, but I do not believe there is any kind of formal policy or prohibition that says to agents, you can only place people on the priority list for the flight during that timeframe between 3 hours and departure. If there is confirmable space, the agent can confirm any member into it. And some kind of automation that prohibits an agent from confirming X inventory during this timeframe is about the only way I can think of to prevent a situation such as Robert Leach's from happening.
In response to the OP, you should always check in online as far in advance as possible. If upgrade inventory opens up, you will still get the upgrade. I've had this happen to me between home and the airport. If it does not clear, you can be placed on the airport priority list which happens to be ordered by check in time within your tier status. So your check in time can be as much as 24 hours in advance....which could make the difference for you in getting the upgrade at the gate if everyone else didn't check in until day of departure at the airport.
Thanks for this perspective, but it still seems sorta screwy to me . . . that an EXP can be checked in and on the list and a seat literally be taken out from under him because he happens to be on a plane at the magical four hour mark, or three hour mark, or whenever it is, by a Gold or Platinum member. In effect, checking in early gets you a higher position on the list, but there is no guarantee that it will ever get to the point where the list is processed, as individual agents all around the system may have snagged seats for favorite customers at the three/four hour mark, essentially prempting the list.
So, in effect, there are two different systems at work. One is the system where there are F seats left to sell but no X inventory available. When the three or four mark arrives, those are made available as X inventory and are basically first-come, first-served; find an agent and he/she can grab that seat for you, regardless of your place on any waitlist. The other system is the waitlist that kicks into play if there are no F seats available at all (even to sell), in which case it boils down to a gate lottery to get the seats of any no-shows. In this case, the list comes in to play and check-in time becomes of paramount importance.