Welcome to the forum, Delfin.
Are you planning to take on the full commitment (that is, cancelling any outsourcing)? If so, you will need four
techs if you hope to do a decent job (with properly conducted PM, and all the rest).
Back in my planning maintenance days I developed various methods of establishing (guessing) how many techs are likely to be needed in various scenarios.
Once (as in your case) the hospital is already up and running it should be easier to quantify the man-hours required "simply" by working out how many hours it takes to PM each item of equipment ... and then adding in some more man-hours for the other (many and various) tasks that biomeds get involved in.
But, rather that waffle on about this and that method - trust me, the "result" will be more or less the same ... that is, a total of four biomeds of average capability (able to act independently, without supervision ... etc.
) - one Senior Technician and three Technicians.
By the way:- how have you been managing so far ... are you able to operate a PM programme (for instance), or are you just "fire fighting" (responding to calls from user staff, equipment breakdowns etc.
I suspect I'm right in assuming that the stuff you currently have outsourced is the more "difficult" kit. So how do you propose to gain the necessary expertise needed before you are able to take on that burden (if that's what you are planning to do)?
I wonder if what we're really looking at here is a (another) case of senior management hoping to make substantial savings, without realising the full extent of the true costs involved in reforming their tech support strategies?
Anyway ... Good Luck. And feel free to come back with more information (as long as you don't mind the candid - but hopefully realistic - responses you are likely to receive)!