IT departments will have to change how they operate, as services delivered via public clouds expand over the next five years.
Business spending on public cloud will see a large increase over the next five years, reaching $66bn by 2015, according to research from Ovum.
Spending on public cloud services - which include using applications from suppliers such as Amazon and Google - will be $18bn in 2011. Ovum said this will grow an average of 29% each year to 2015.
IT departments will use clouds created and supported by third parties. This will mean they focus less on maintenance and more on innovation, said Laurent Lachal, analyst at Ovum.
He said IT departments will be tasked with connecting networks, hardware and software.
"The impact of public clouds will not be to render IT departments obsolete, but rather to shift their focus," said Lachal.
"Shifts will include taking a more holistic approach to connecting networks, hardware and software. IT departments will also reduce their emphasis on maintenance and increase their innovation, while being encouraged to take more risks, by giving employees the capacity to tackle high-reward ventures," Lachal said.
Despite private cloud service adoption outstripping public clouds, large businesses are now considering public cloud for parts of their IT infrastructures.
Mark Lewis, lawyer at Berwin Leighton Paisner, told Computer Weekly that large companies are now considering cloud for applications as and when they need to refresh. He said public cloud services from the likes of Amazon, Google, VMware and Microsoft are being considered.
"It is happening slowly but it is happening," he said. "Some very large companies are looking at their IT infrastructure because they have not renewed for a number of years.
Anjan Lahiri, IT services CEO at tier-two Indian service provider MindTree, also said there is a slow acceptance of applications in the public cloud.
"Innovative and new applications are candidates for the public cloud, but they are not rushing out the door to put things in the public cloud."
He said infrastructure applications such as e-mail, anti-virus and storage are being considered for public cloud. But in terms of core customer systems, Lahiri does not see any change from what is happening now.