From time to time, the forensics department at professional services firm KPMG must sift through vast amount of extremely sensitive client data.

The results can be impressive. A recent job for a FTSE100 company recovered £50 million in revenue from incorrect billing items by cross referencing half a billion rows of transactional data with 15 million customer records. But those results require an equally impressive supply of processing and storage capacity on an ad-hoc basis.

“Forensics has different requirements to traditional storage implementations,” explains Darren Pauling, director of KPMG Forensics. “You might need it, but then not need it [for some time]. We had to find an innovative approach that would offer us flexibility and not cost the earth – and something we could turn on and off.”

Outsourcing the management and supply of the processing and storage equipment to a third party made sense from an economic perspective. “We simply didn’t have the resources in-house to expand the operation as fast as we wanted,” Pauling recalls.

But KPMG’s stringent security requirements made finding a suitable partner difficult. After a gruelling three year tender and due diligence process, the division eventually took 16 racks with managed hosting provider ControlCircle.

“Many clients insist that we lock our system so that only the people we decide have access can see the data,” Pauling says. As well as an encrypted, firewalled front-end, the team had to ensure that “at no stage would ControlCircle have sight into any data put onto the platform.”

“Our system is completely standalone in their data centre, inside a cage,” he explains. “We have biometric access into each separate area purely for KPMG staff and clients.”

Physical security extends beyond floor-to-ceiling caging and elaborate access locks to under-floor barriers, CCTV and a link that allows KPMG itself to monitor the facility.

The managed services solution, KMPG data analytics partner Stephen Gallagher estimates, is “conservatively” 15% to 20% less expensive than an in-house alternative because it scales to meet demand.

“In the old days, we would have had to add to our systems as we went along, which wasn’t a sustainable way of working,” says Gallagher. “The beauty of the new platform is we’ve now got an infrastructure which is totally flexible.”