Go forth armed with clipboard and stopwatch and study an actual waiting experience (e.g., post office, fast-food restaurant, retail bank). Begin with a sketch of the layout noting the queue configuration. Describe the characteristics of the calling population and the queue discipline in use. For the arrival process, take a large enough sample of the time in minutes between arrivals to determine if the distribution between arrivals is distributed exponentially (or arrivals per hour are Poisson distributed). Collect a sample of the service times to determine if they are distributed exponentially.