Queuing theory is the study of the mathematical theory and the methods of queuing systems is an important
branch of operations research. Any one of the basic queuing process of the queuing problem can be expressed in
Figure 2.1. Port ships arrive at the ports, and wait for the process of handling services. It can also be seen as a
queuing process, the port ships are equivalent to the customers, the handling facilities are equivalent to service
desks, shown in Figure 2-1. The figure describes each ship reach the port pier in a certain way, first, join the queue
and wait for handling services. Service desks select the ships to load and unload from the queue in certain rules, then
the ships which after completion of handling left.
then the ships which after completion of handling left.