Air New Zealand management will seek answers from IBM on Monday after a failed back-up generator saw 10,000 passengers stuck waiting in queues across the country on Sunday.
Passenger check-in kiosks, call centre systems and online bookings system crashed at 9am on Sunday, forcing airline staff to check tickets manually.
The backlog of passengers was not cleared until 4pm.
Airline short haul manager Bruce Parton says IBM's performance has fallen well short of expectations.
He says customers rely upon airlines to be efficient and they in turn expect their suppliers to be the same.
Mr Parton says they know what went wrong, but want to know why it took more than six hours to re-establish the full system.
In a statement, IBM said the problem was a back-up generator at a data centre at Newton in Auckland which experienced power failure.
IBM says the generator was running again within three minutes, but one client's system in particular was badly affected.
Air New Zealand introduced self-check machines last November, at a cost of $30 million.
Mr Parton describes the situation on Sunday as a "full-blown system meltdown".
Air New Zealand says it's studying how well it kept customers informed during the computer failure.
Some passengers say they were not told of the delays before arriving at airports.
The carrier has told Morning Report it will look at the possibility of customer compensation.