Some Queuing Problems Queuing is a ubiquitous feature of electronic systems such as computers and communication networks. Queues will build up, even if the capacity of the system exceeds the load on it. This is an inevitable consequence of the fact that arrivals and services take place in a random fashion. Indeed, the more random the services and the arrivals are, the more queues build up. Thus, it is possible for long queues to develop at even light loads, arising as a consequence of sheer variability in the pattern of arrivals and services.