ABSTRACT
Queues appear in many aspects of life. Some are clearly visible, as in the queues at supermarket check-out tills: others may be less obvious as in call-stacking at airline information telephone lines, or in hospital waiting lists. In the latter an individual waiting may have no idea how many persons are in front of him or her in the hospital appointments list. Generally we are interested in the long-term behaviour of queues for future planning purposes—does a queue increase with time or does it have a steady state, and if it does have a steady state, then, on average, how many individuals are there in the queue and what is the mean waiting time?
