Transactions

Attributes

You assign an attribute to a transaction in the Modifier component. There are three types of attributes: numeric, character, and unevaluated formulas. An attribute is attached to the transaction for the duration of the transaction, but it can be given another value at any time.

History

The transaction maintains a history of the time it has spent traversing the network. This history is saved in transaction attributes. For example, when a transaction enters a queue, it records the time it entered the queue in an attribute that is named in the queue control panel (see Figure 3.5). When the transaction leaves the queue, it updates the attribute with the total time it spent in the queue. When a transaction enters a Bucket, if the Collect Data check box is set (see Figure 9.8), then any attribute in its history can be written to a SAS data set. You have to name the attribute for which you want to save data in the bucket control panel.

By default, the total age of the transaction is also a part of its history. This is the quantity that is, by default, collected in Buckets. You can access it with the attribute named "age."

It is important to note that the transaction only spends simulation time in queues and servers. All the real time that is spent in other components and traversing arcs do not result in passage of simulation time.