If your trying to cover one unit. you will need at a minimum of (9) nine emt-b's. That will give you one unit on call 24/7 with the personal on duty 24 hrs. on 48 hrs. off. If you add a supervisor you'll have 10 personal. From that point on if you add another uint you'll add 9 emt-b's for each unit you need the field. Plus one supervisor/shift. Unless your talking about one man units. That would mean you only need (1) person per 24 hour shift. With one man units you may be able to use less supervisors.------Hear endeth the lesson. Passin.