The cost of having staff book trips using online booking tools is "horrendous", Ron Mitchell, UK procurement consultant for Zurich Financial Services, told the conference.
At a time when travel management companies were losing commissions from airlines and seeking to reduce their overheads, they had "sold" the idea of self-booking tools to corporates, he claimed.
"They were sold as a way of applying 'visual guilt' to the bookers and this would reduce their fares.
"What they were saying was, 'Get all your guys to book their own travel and we can reduce our overheads by getting rid of travel counsellors.' So the main beneficiaries were the TMCs," Mitchell argued.
But, he added, it took a fully trained counsellor on £15,000-a-year, five minutes to book a simple point-to-point trip, while the traveller, who could be on £50,000 to £60,000, spent 15 to 20 minutes making the same booking.
"You have to question what you are getting out if it and why you are doing it. The cost of these tools is horrendous," he said.
Matthew Frost, UK sales director for KDS, said it was difficult to compare the time it took to make a booking online with the time a traveller spent on the phone to the agent. "He is going to spend as much time on the phone listening to the options as he is in making the booking."
Chris Reynolds, a consultant with 3Sixty, said that "SBTs are a necessary part of a management toolkit".