The common measures of a queuing system's performance include
◦ probability that the service facility will be idle, average queue length, probability that the waiting time will exceed a specified duration.
◦ average time that the service facility is idle, minimum queue length, probability that the waiting time will exceed a specified duration.
◦ average time each customer spends in the system, probability that the service system will be idle, average time each customer spends in the queue.
◦ average time each customer spends in the system, maximum queue length, probability of a specific number of customers in the system.
◦ average queue length, maximum time a customer may spend in the queue, the utilization factor for the system.