Hi Max,
What arrangements does your hospital have in place if say a defib goes down in the middle of the night? Do the users swap/ borrow equipment from a library or store room? Also what happens if you have a major failure with the central monitoring on ITU, do the staff just work around it?
One suggestion that has been mooted is that BME depts. work shifts & provide weekend cover as part of their normal duty. This would remove the need for on-call, but wouuld probably cost more in terms of number of staff & unsocial working.