Model 4: Multiple servers with infinite waiting room Model 4 (M/M/s Queue): Multiple servers, Infinite population, Poisson arrival, FCFS, Exponential service time, Unlimited waiting room Yellow cells need user inputed values Inputs Unit of time Arrival rate (lambda) Service rate (mu) Number of identical servers (s) hour 16 customers per 20 customers per 2 servers hour hour Outputs Direct outputs from inputs Mean time between arrivals Mean time per service Traffic intensity Summary measures Average utilization rate of server Average number of customers waiting in line (Lq) Average number of customers in system (L) Average time waiting in line (Wq) Average time in system (W) Probability of no customers in system (P0) Probability that all servers are busy Probability that at least one server is idle Distribution of number of customers in system n (customers) 1 Distribution of time in queue t (time in queue) 0.3333333333 0.063 hour 0.05 hour 0.4 40.0% #NAME? customers #NAME? customers #NAME? hour #NAME? hour #NAME? (this is the probability of empty system) #NAME? (this is also the "percentage who wait in queue") #NAME? (this is also the "percentage who don't wait in queue") P(n in system) #NAME? P(wait > t) #NAME