Re: The NHS
"Turns out the old clunker was certified as an integral part of some medical kit, and it was cheaper to round up second hand machines than re-certify them with new kit."
OTOH while it might have been certified when new after 6 years it might have been heading for FCS (Fat Capacitor Syndrome) or some other ailment of ageing IT kit. Maybe a H/W certification should be time limited to reasonable life after which it should be replaced. It would build the recertification with a new model and replacement of the installed units into the financial planning of the system.
In fact, although I was thinking only in terms of hardware reliability when I wrote that building recertification of the computer element into the life of a system would also make provision for updating the OS as well as the H/W.