ABSTRACT
This chapter explores the incorporation of variability into models of business processes. It describes some commonly used queuing models and how they can be applied. Queuing processes, queuing systems, and queuing models might appear to be abstract concepts with limited practical applicability, but nothing could be further from the truth. The class of transportation service systems represents situations where vehicles are either customers or servers. In business-internal service systems , the customers receiving service are internal to the organization providing the service. A conceptual model of the basic queuing process describes the operation of the queuing systems just mentioned and further, explains the subtle distinction between a queuing process and a queuing system. The basic queuing process describes how customers arrive at and proceed through the queuing system. Customers or jobs from a calling population arrive at one or several queues with a certain configuration.
