5-10 of her aircraft are currently on acceptance trials with whatever they're calling the RAF/RN joint operations lot nowadays.
I believe we've got another 20-odd on order to turn up in the next year. To give 2 squadrons for operational testing next year. At some point we're then going to borrow 2 squadrons of the US Marine's ones - so that we can both test joint operations, and test what it's like to have a carrier full of 48 planes plus helicopters. So I guess they're aiming for operational by 2019-2020. At which point we'll have at least 2 squadrons operational, plus one or two more in training on their new toys.
We're then supposed to be up to 150 aircraft by 2028 or something - at what schedule I've no idea. They may have back-loaded the orders, so that the defence budget balances for the next few years, or they may just be taking them to fit the production schedule.
Normal deployment is expected to only be with only 24 aircraft - given that if they need more for operations, then more can be flown in.
I don't know if doctrine will change - and we'll end up with squadrons specialising in carrier and RAF ops after trying this joint thing out. But we did operate a joint Harrier force for the last while before it was scrapped - though I can't think of any other Navy that's done it this way. The advantage is you get a larger and more flexible force - they shoved extra planes above their capacity on the 2 carriers that went to the Falklands for example.
Plus carrier ops are really hard on planes, so they only last half as long as land-based ones. If you mix the ops each plane does, then you'll get a longer lifespan out of all of them.