Tesco has launched a review of its IT strategy after discovering that Wintel platforms accounted for 29% of its IT carbon footprint compared with 3% for mainframes and 18% for storage systems.
Tesco is moving its existng Wintel systems to virtual servers as an interim step, before deciding which technology platforms, including mainframes, will be most efficient for its applications in future.
It plans to look at application functionality, not just infrastructure, and to decommission and simplify operations.
The review is a response to chairman Terry Leahy's aim to halve Tesco's 4.1 million tonne carbon footprint by 2020. About 4% of Tesco's total carbon footprint is generated by IT.
Virtualisation is expected to raise the utilisation of Tesco's Wintel servers from 6% to 60%. The programme would see the number of Wintel systems in datacentres slashed from around 1,500 systems to between 150 and 300,
The shift to virtualisation began a couple of years ago, but Tesco is now going at it much more aggressively.
"Big changes will happen between now and end-2009," said Mike Yorwerth, Tesco's director of group technology and architecture.
"We are virtualising our Wintel estate and will also be considering what we could do around the mainframe side given its efficiency," he said. Tesco achieves 98% utilisation on its mainframe systems.
"Currently we have no plans to switch over current apps, including point of sale, from Wintel to mainframe," said Yorwerth. "Our overall strategy is still forming in this space."
Yorwerth said that all future Wintel apps and many if not all current Wintel apps would sit on hypervisors (virtualised platforms), with a standard hardware and software build.
"By standardising on a virtualised platform rather than having it as a 'special', we will simplify the operation significantly," he said.
In April 2007 the retailer announced that it would standardise its IT estate to provide the same operating environment in stores worldwide.
The aim is to run all applications, such as Oracle Financials, PeopleSoft staff management and Teradata data warehousing, from its IT service centre in Bangalore, India.
Last month Tesco signed a £100m managed network deal with Cable & Wireless to simplify, centralise and streamline its global communications.