Mr Doyle said the upgrade will seek to take an “omni-channel” approach, with people getting the same familiar experience via the new app, on BA.com, or when viewing the website on their mobile phone.
The aim will be to match the convenience of the “three clicks and you can check out” approach of online retailing pioneered by the likes of Amazon, he said.
People taking a family holiday are likely to continue to use the website, but the app should become the primary resource for those making regular trips, such as business travellers.
Mr Doyle said: “The most important thing about an app is that the repeatable processes, that people rely on time and time and time again, work well.”
The digital upgrade will also allow travellers to undertake every single transaction online, compared with about 70pc today, he said. That will include the ability to rebook, claim a refund and cancel flights.
British Airways will seek to avoid the pitfalls experienced by US ally American Airlines, where a new system aimed at maximising direct bookings and reducing reliance on intermediaries generated less revenue than expected owing to its complexity.
The slip-up, which hurt late bookings from corporate travellers, sent American Airlines shares down 16pc last Wednesday and led to the exit of its chief commercial officer.
In tandem with the digital makeover, British Airways is upgrading inflight entertainment, introducing a new cabin in its fleet of Airbus A320-series short-haul planes, its workhorse on European routes, and opening new airport lounges in Dubai, Miami, Lagos and Seattle.
A revamped first-class cabin will also be introduced on BA’s A380 superjumbos later this year, while about half of the value of the modernisation plan, or £3.5bn, will be spent on new planes.