IAG expects over half of the roll-out programme for British Airways' business-class reconfiguration to be completed within the next two years.
But the company admits that it has been facing internal pressure to accelerate the deployment.
IAG chief financial officer Steve Gunning, speaking during an 8 November briefing, said the roll-out was an "enormous logistical exercise".
"I don't think people quite get the gravity of it," he says, pointing out that over 7,000 seats are being fitted.
Gunning says that even the board has queried whether the installations can be carried out more quickly. But he states that the supply chain from the seat manufacturer is the "critical path" and that the exercise is "quite a challenge".
BA started introducing the new Club World seat on its Airbus A350s and Boeing 777-200ERs this year.
"One of the areas we've really known we have to strengthen is the business-class product," says Gunning.
The reconfiguration plan will extend to the 777-300ER and 787-10 in 2020, and the 787-8 and -9 fleet from 2021-22. BA's new 777-9 fleet will be equipped with the seats when the type is introduced from 2022.
BA's Airbus A380s will be the last to undergo the revamp, from 2023, the year before the airline withdraws its Boeing 747-400s.
Reconfiguration of the business cabins across the fleet will be complete in 2025.
Gunning is confident that, although the new cabin is less dense, at four-abreast, than the current "yin-yang" layout featuring opposite-facing seats, the change will not hit profitability.
He says a BA reconfiguration analysis found first-class capacity offered was not justified by the low load factors, and the carrier opted to shrink this cabin and use the freed space to extend the business-class section.
On the 777-200ER the aircraft's first-class seating is halved and the forward galley area narrowed to avoid any loss of business-class seats.
BA has retained the same 40-seat premium-economy cabin because, says Gunning, it is "almost as profitable" as the business cabin on a per-unit area basis.
The aft economy cabin has been refitted with 10-abreast seating – "competitors have already done it", says Gunning – taking accommodation from 124 to 138. Overall the 777-200ER's passenger seating increases from 226 to 235.
"We were very comfortable…that our cabin reconfiguration programme was going to be profit-enhancing, not profit negative," Gunning adds.