Yes Dave ... the tools are there (for those who care to use them).
As I may have mentioned many times before, "Risk" is the answer. That is, each equipment type needs to be assigned a *Risk value (or factor):- Low, Med, High (or some more elaborate regime).
I believe it is easier to include "everything" on the inventory (database, dependency, whatever) then allow for a system whereby PM intervals may be adjusted according to need. For example, a PM interval of 999 days more or less equates to a policy of "repair when broken", even though a PM programme remains in place.
More advanced applications of Risk-Based PM allow PM intervals to be adjusted (lengthened or reduced) as time passes (PM cycles pass) depending on the condition of the equipment during recent PM visits.
Also, I always advise that each item of equipment be allocated a statement (which can, or should, be just a simple code) about how it is to be maintained - a "Maintenance Support Policy", if you like. That way, everyone involved can be made aware about how the item is to be maintained; and yes, it could be "on contract" ... or even "discard when broken" if you prefer!
Again, as I have mentioned before (sorry folks), to my mind one of the essential elements of a PM programme is that the technician comes into contact with each item of equipment on a regular basis!
*
Perceived risk to the patient in case of equipment failure.
