| Getting Started |
Service
When the transaction arrives at the Server,
service is scheduled and the transaction ties up
the server.
By default, the service time is an observation of an exponential
random variable with parameter 1.
Both the service distribution and its parameters
can be changed using the server's control panel.
While the server is serving this transaction, any
"are you busy" messages sent to it result in a "yes" response.
When service is complete, the server sends the transaction
on any arcs directed away from it and also sends a message
up the arcs directed into it requesting an additional transaction.
In this example, if the FIFO Queue is not empty,
it will remove the transaction that has been there the longest
and send it to the Server.
By default, all queues in the system have a capacity of 50
transactions.
Of course, this capacity can be changed through the user
interface or programmatically, as discussed in the next chapter.
Since by default the inter-arrival times and the service
times are 
, exponentially distributed with mean 1, the transaction
time in the system would not have a stationary distribution
if the queue had infinite capacity.
Copyright © 2008 by SAS Institute Inc., Cary, NC, USA. All rights reserved.