An Item Property is the only attribute of an Item Flow. An Item Flow describes the flow of items across a Connector or an Association. If an Item Flow is assigned to a Connector, you can specify an optional Attribute, Item Property, to relate the flowing item to the instances of the Connectors’ enclosing Block. Item Flows and Item Property are defined on Connectors in the SysML Internal Block Diagrams.


To create an Item Flow with the Item Property tag initialized on a Connector


  1. Do one of the following:
  2. In the Item Flow/Item Property dialog, specify the following options:
    • Item Flow. From the drop-down menu, select an existing Item Flow or create a new one by selecting <NEW>.

      If you select an existing Item Flow, you don't need to specify the rest of the options in this dialog.

    • Direction. From the drop-down menu, select the direction of the new Item Flow.
    • Conveyed Classifiers. Click From the Select Conveyed Classifier dialog, select a classifier to be used as the Conveyed Classifier. Click OK.
    • Item Property. Click From the Select Item Property dialog, select a Part Property to be used as the Item Property. Click OK.
  3. Click OK.

    An Item Flow with the selected property as its Item Property is created and is set for the Connector (see the following figure).

    If you want to reverse the Item Flow direction and update it in all related diagrams, read Reversing Information Flow direction.

The Action Item Flow is created and set for the Connector in the Regulation Loop Principle Internal Block Diagram.


If the name of the Item Property is not displayed on the Item Flow, you must perform the following actions.


To display the Item Property name on the Connector


  1. On the diagram pane, select the connector with the Item Flow assigned.
  2. Right-click it to open a shortcut menu and select the Edit Compartments command.
  3. The Compartment Edit dialog opens. In the dialog, select the Information From tab depending on the flow direction.

    Scrolling trough tabs

    Use Scroll Backward and Scroll Forward arrows to move through tabs or click the Show list button to see the list of all tabs.

  4. In the Hidden list, select Item Property names you want to see on the Item Flow and move them to the Selected list. 
  5. Click OK.

Sample model

The model used in the figures of this page is the TemperatureRegulationLoop sample model. To open this sample do one of the following:

  • Download TemperatureRegulationLoop.mdzip.
  • Find in modeling tool <modeling tool installation directory>\samples\SysML\TemperatureRegulationLoop\TemperatureRegulationLoop.mdzip.