Question 3: Case Study - Operating Room Staffing at American University of Beirut Medical Center The American University of Beirut Medical Center (AUBMC) in Lebanon is certified by US medical boards. Like similar hospitals internationally, it must meet standards such as the American College of Surgeons' criteria for operating rooms. Level I and Il trauma centres are required to have an operating room (OR) staffed 24 hours per day. A base level of at least one OR team available 24 hours a day is mandatory. During normal business hours, AUBMC will typically have additional OR teams available, since surgery is scheduled during these times and additional teams can be used in an emergency. An important decision must be made concerning the availability of a backup team during the evening hours. A backup team is needed during the evening hours if the probability of having two or more cases simultaneously is significant. "Significant" is difficult to judge, but for the purposes of this case assume that a backup OR team should be employed if the expected probability of two or more cases occurring simultaneously is greater than 1 percent. In one published year-long study, emergency OR patients that arrived after 11 p.m. and before 7 a.m. were studied in a hospital similar to AUBMC. During this time period, there were 62 patients that required OR treatment. The average service time was 80.79 minutes. In analyzing the problem, think about this as a single channel, single-phase system with Poisson arrivals and exponential service times. a) Calculate the average customer arrival rate and service rate per hour. b) Calculate the probability of zero patients in the system (PO), the probability of one patient (P1), and the probability of two or more patients simultaneously arriving during the night shift. c) Using a criterion that if the probability is greater than 1 percent, a backup OR team should be employed, make a recommendation to hospital administration