On this page

Creating Item Flows

The following procedure showcases how to create Item Flows whether you are working with the Direct or the Between Part Types creation mode.

To create an Item Flow 


  1. Do one of the following:
    • Select a Connector (in Direct mode) or an Association, Connector, Message, Control Flow, or Object Flow (in Between Part Types mode) on the diagram pane, and on its smart manipulator toolbar, click .
    • Drag the classifier you want to use as the Conveyed Classifier onto the intended Connector.
  2. In the Create/Edit Item Flow dialog, Create new or Select Existing Item Flow step, 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.

      If you are creating the Item Flow on the directed relationship, the Direction is set automatically and is not available for editing.

    • Conveyed Classifiers. Click From the Select Conveyed Classifier dialog, select a classifier to be used as the Conveyed Classifier. Click OK.

      If you have invoked the Create/Edit Item Flow dialog by dragging a classifier onto the Connector and do not want to change it, you may skip this option.

    • (Optional) Item Property. Click From the Select Item Property dialog, select a Part Property to use as the Item Property. Click OK

      This option is available when creating an Item Flow in the SysML Internal Block Diagram.

  3. In the Specify Activities step, add the activities.

    • This step is available only in the Between Part Types creation mode.
    • This step is not available if you are creating the Item Flow between Part Properties with no types set.

  4. Click the Update Diagrams step if you want to select which diagrams should show the newly created Item Flow. Only the diagrams that display the elements realizing the Item Flow are available for selection.

    The Update Diagrams step is disabled if the Conveyed Item is not specified in the first step.

  5. Click Finish. An Item Flow with the selected Conveyed Item (and Item Property if it was defined) is created and is set for the Connector.

    • If, however, there are no diagrams with the activity pairs specified in the Specify Activities step, you will get a suggestion to have the diagrams created.

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

Showing/hiding the Conveyed Item

You can choose to show or hide the Conveyed Item on the element realizing the Item Flow (Association, Connector, Activity Edge, Message).

To show/hide the Conveyed Item


  1. On the diagram pane, select the element realizing an Item Flow.
  2. On the smart manipulator toolbar:
    1. If the Conveyed Item is not displayed, the tooltip for the button isShow Realized Item Flows. Click it to show the Conveyed Item.
    2. If the Conveyed Item is displayed, the tooltip for the button is  Hide Realized Item Flows. Click it to hide the Conveyed Item.
      If the element realizes only one Item Flow, the Conveyed Item is displayed/hidden instantly with the click of a button.
  3. If the element realizes multiple Item Flows, the Conveyed Items menu opens. In it, do the following:
    1. Select the check boxes for the Item Flows whose Conveyed Item you want to be displayed.
    2. Clear the check boxes for the Item Flows whose Conveyed Item you want to be hidden.

      To select all check boxes, click the Select All button. To clear all check boxes, click the Clear All button.

    3. Click OK.

Realizing Item Flows

You can realize hidden Item Flows in two ways:

  • Through the Item Flow Manager.
  • From the selected relationship's Smart Manipulator toolbar.

To realize Item Flows through the Item Flow Manager dialog


  1. Select an Association, Connector, Control Flow, Object Flow, or Message in the diagram pane.
  2. On the smart manipulator, click  . The Item Flow  Manager dialog opens.
  3. Do one of the following:
    • Set the Realize column option to true for those Item Flows you want to realize.
    • Click the Realize All button, if you want to realize all Item Flows.
  4. Click Close when you are finished.


To realize Item Flows from the Smart Manipulator toolbar


  1. Select Association, Connector, Association, Control Flow, Object Flow, or Message in the diagram pane.
  2. From the Smart Manipulator toolbar, select  Realize All Item Flows.

Removing not realized Item Flows

If you remove the realizing elements from the model, the no longer used Item Flows are left as a residue. However, you can specify the Remove Not Realized Item Flows project option to remove Item Flows automatically after the last element that realizes them is deleted.

To specify the Remove Not Realized Item Flows project option


  1. In the Main toolbar, click Options > Project. The Project Options dialog opens.
  2. In the General tab, select SysML.
  3. Set the Remove Not Realized Item Flows option to true. The default value is false.

To find all not realized Item Flows, you can run the 'SysML ValSuite - Ports and Flows' validation suite. The Not Realized Item Flow validation rule will check for any residual Item Flows.
Learn more about starting the validation >>