One member of MOD's Governance Team expressed surprise regarding a project with which I was involved recently, because the life was in the order of 20 years. It was/is quite heavily IT focused, though relatively specialist in nature. He was reassured that there was expected to be a need for a 'Tech Refresh' at or about the 10-year point. Ten years is about the maximum he would expect an 'IT Capability' to last in service.