Transaction (T. or no prefix)

These attributes are associated with transactions that flow through a process during simulation. A change in the value of a transaction attribute for one transaction does not affect the value of the same attribute for other transactions.

You can, however, set Transaction attribute values for transactions that belong to the same transaction family to the same value simultaneously using a special prefix (F.) before the attribute name (see Attribute Names).

For example, transactions could represent product orders and a transaction attribute could contain the order size.

Argument (M. or C.)

Arguments are associated with a Callable Process. You may think of, and use, arguments like attributes that are associated with a callable process, and are available for use by the transaction (or transaction family) in the callable process instance. Each instance of the callable process will have unique values for its arguments.

There are two sub-locations of argument attributes: M. (My) and C. (Child):

• The My (M.) argument attributes are only available to the callable process, and their values are unique within the process instance; i.e. for the current transaction or transaction family in the callable process.

• The Child (C.) attributes are only available when a callable process is accessing the arguments of a child process that is also a callable process. This distinguishes arguments in the child process from arguments in the current (My) process.

Scenario (S.)

These attributes are global within a scenario. If any activity included in the current scenario changes the value of a scenario attribute, the value is changed for all elements of that scenario. A change in a scenario attribute in one scenario does not affect the value of the same attribute in other scenarios.

For example, you could count transactions processed by an activity and then use that count elsewhere in the model.

Activity (A.)

Activity attributes can be used to store information about an activity during a simulation. For example, if each of your transactions have a weight attribute, you could keep a totalWeight on the activity so you could tell how much total weight the activity had processed. Activity attributes can be initialized using Shape Custom Data Values (see Activity Attributes).

To define an activity attribute, use the Define Attributes dialog box. To assign a value to an activity attribute, use the Properties dialog box - Attributes page.

Resource (R.)

A resource attribute can be used to store information about a single resource during simulation. For example, a resource could have a Skill attribute that increases as the resource is used to do a task. Resource attribute values are initialized on the initialization section of the Define Resources dialog box - Attributes tab. They can be used in expressions, such as the Constraint expression when acquiring a resource in the Properties dialog box - Resources page.

To assign to a resource attribute use the Define Resources dialog box - Attributes tab.