I agree with all mentioned above but would like to add:
Once upon a time when I was a kid and used to work in a particular restaurant, we would pre-cook the ribs, cool them completely, and trim some of the hardened fat. Then when an order would come in, we would place a rack on a lined sheet tray, smother it in BBQ sauce, then place the tray into a 500 degree oven until the sauce bubbled and set (about 6-8 minutes). We sold out every night!