He believes organizations need to appoint a full-time 'relationship manager' to remove dependencies on consultants.
"It is too expensive to keep IT inhouse but it has to be done properly by appointing a relationship manager," Zarella said.
"Because this is a new title there is a serious shortage of people with vendor management skills, the days of a contract manager working in accounts payable is long gone.
"Also the person that does the deal and develops the contract should not be the person managing it afterwards."
The study supports Gartner research which claims IT departments are shrinking as IT professionals move into specialists roles such as vendor management.
In the future, an IT career will not be about technology but managing a range of service providers.
By 2010, IT organizations in large and midsize companies will be 30 percent smaller, according to Diane Morello, vice president of research at Gartner.
"Partly driving this trend is outsourcing and IT automation," she said.