Travel is becoming a strategic investment where the travel manager needs to measure the total cost of a trip, Herman Mensink said.
This "value management" was a new, emerging role for travel managers, the vice president of the Prism Group said.
A "key principle" in it was for travel managers to arm the line managers with data so they could make the decision on whether their staff should travel or not.
This was necessary to achieve the maximum value from a trip, Mr Mensink told the Association of Corporate Travel Executives' (ACTE) global education conferenced in Rome.
Travel managers need to tell senior executives that year on year savings on travel budgets were not possible.
Corporates have to recognise there must be a balance between costs and the needs of the business, Mr Mensink said.
"The traditional travel managing role is moving into value management. The first thing in travel value assessment is to analyse the total travel base and then create new tools to deal with it," he said.
Travel managers needed to collect two to four months of data of their company's trips and patterns and then benchmark it.
"They can then go to the line managers and senior management with the data. They should be constantly asking the line managers 'What is the reason for this trip?' 'What do you want to get out of it?'
"You must follow up on each trip," Mr Mensink said.
"One of the most important things is that you leverage the experience and knowledge that you have with the line managers rather than focusing on strategic sourcing and budgeting."
But Marc Hochman, a partner with consultants A T Kearney said a recent survey by his company found that no companies were measuring their return on investment (ROI) in travel.
"50% said it was too difficult to measure while the other 50% said it was too difficult to get the data. Data is king but getting it is extremely difficult," he said.
Mr Hochman said the survey also found that companies were using technology to reduce travel spend with 50% saying they had specific policies for this. Most were using conference calls and video and web conferencing but none said they used collaboration tools, like Sharepoint.
"These are now being used in a lot of industries and it bothers me that it is not happening in travel. You need to get familiar with them," he told the delegates.