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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 or an Association (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 Item 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.
      • If you are creating the Item Flow between an Activity Parameter Node and an Action, the Direction field displays suggested sender/receiver elements based on the element typing the parts to which actions are allocated.

    • Conveyed Items. 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.

    • (Optional) Add Item Flow to corresponding relationships. Select the check box to synchronize the Item Flow for Associations, Activity Edges, Connectors, and Messages with appropriate Item Flow ends. 

  3. In the Edit Item Flow Realization between Activities step, review the activities. 

    • If the Add Item Flow to corresponding relationships option is selected and multiple Activity Pairs are detected, remove the unnecessary pairs via the Remove From Table button.

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

  4. Click Review or update affected diagrams to see the list of diagrams where the selected Item Flow can be realized and displayed. You can choose one or more diagrams you want the specified flow to be displayed. If the diagrams are grayed out, this means there are no Conveyed Items of the selected Item Flow to be displayed. 

    • The project option Show Item Flows on Affected Diagrams controls how the diagrams will be updated for newly created or modified flows. By default, the option is set to true to update all affected diagrams and show the Conveyed Items of Item Flows whenever a new flow is created or an existing one is modified.

    • To learn more about previewing affected diagrams, see Preview Affected Diagrams dialog.

  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 and the corresponding relationships if the Add Item Flow to corresponding relationships was selected.

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

Specifying the Conveyed Item directly on the diagram pane

You can also specify a Conveyed Item directly on the diagram pane if you have already created an Item Flow.

To specify the Conveyed Item directly on the diagram pane

  1. In the diagram palette, select the needed Conveyed Item.
  2. Drag the selected Conveyed Item onto the Item Flow on the diagram pane. The Create/Edit Item Flow dialog opens. If the Item Flow already has Conveyed Item(s), the Conveyed Items field is appended with the new item.
  3. Follow the steps of the dialog. See the Creating Item Flows procedure steps 2-4.
  4. Click Finish when you are done. 

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.

When you hide the realized exchanges, you can choose whether you want to hide the arrow notation on the realizing elements. The Hide Information Flow If Conveyed Information Is Missing project option controls the arrow visibility.


To change the arrow notation visibility on realizing element when the Conveyed Item is hidden or unspecified

  1. From the modeling tool main menu, choose Options > Project. The Project Options dialog opens.
  2. In the dialog, go to General > Diagrams.
  3. In the Diagrams property group, find the Hide Information Flow If Conveyed Information Is Missing option and set it to true.
  4. Click OK when you are done.

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 >> 

Navigating to diagrams where Item Flow is realized

To navigate to diagrams where Item Flow is realized

  • Right-click the Item Flow element and in its shortcut menu, select Go To, then Usage in Diagrams, then Realizing Elements, then select the realizing element type. In its submenu, select a diagram in the displayed list.