Cadence. A new case can start every max( (prep + operative + close + turnover) ÷ 2, operative + 5 min walk ). If the surgeon term is larger, the model is surgeon-limited (rooms feed faster than the surgeon can operate); if the room term is larger, the model is room-limited (the surgeon waits between cases).
Cases per day. Hard stop at 3:00, so only cases whose patient is out of the room by then count. The first is out at prep + operative + close; one more lands every cadence after. Turnover after the last case is ignored.
Surgeon use. Operative minutes actually performed ÷ the 480-min day (cases × operative ÷ 480).
Room utilization. Each room's OR utilization is the number of cases it runs × the full case cycle (prep + operative + close + turnover) ÷ 480. Cases alternate between rooms — Room A takes cases 1, 3, 5… and Room B takes 2, 4, 6… — so when the day fits an odd total, Room A runs one more case than Room B and will show a slightly higher utilization.
Assumptions. The surgeon is needed only skin-to-skin; prep, emergence and turnover run in parallel in the other room with a second team. Times are fixed — no variability, delays, add-ons or emergencies — so this is a best-case ceiling. The multiplier never quite reaches 2×, since the first case's prep is never hidden and the last case needs its full tail.