ABSTRACT

The queue ADT that we looked at previously can be thought of as modeling a service line. All the entities that are added in are considered equal, and they are taken off in the order they arrive. Not every system works in such an equitable way. In real life there are things like VIP lines. Some systems have a serious reason to treat entities differently. An example of such a system is an emergency room. If you show up to an ER with a paper cut, you can expect to wait for a very long time. This is because the order in which people are served in a ER is based much more on the seriousness of the person’s condition than on the time of arrival. Situations where people set up appointments are another example. Arriving long before your appointment time generally does not lead to you being seen significantly earlier.