UML Modeling Techniques > Class modeling > Associations and io flows > Specifying that an io flow is realized by an item
  
Specifying that an io flow is realized by an item
You can specify that an IO Flow is realized by an item through a diagram and through the Links Editor.
To specify that an io flow is realized by an item through a diagram:
1. In a Modeler pane, locate the IO Flow.
2. On a diagram, locate the Association, Control Flow, Exception Handler or Object Flow.
3. Drag the IO Flow from the Modeler pane to the Association, Control Flow, Exception Handler or Object Flow on the diagram.
4. If the direction of the IO Flow's arrow is pointing the wrong way: right-click the IO Flow, and then click Reverse Direction.
Alternatively,
1. On a diagram, locate the Association, Control Flow, Exception Handler or Object Flow.
2. On the diagram toolbar, click the IO Flow Realization button.
3. On the diagram, right-click on the Association, Control Flow, Exception Handler or Object Flow, and then click the appropriate command:
If there is a command for the required IO Flow, click that command.
If there is not a command for the required IO Flow, click Other, and then select the IO Flow.
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If an IO Flow is populated on an Association and that Association is not realized by the IO Flow, which can happen on a Composite Structure Diagram, Modeler sets up the IO Flow to be realized by the Association.
To specify that an io flow is realized by an item through the links editor:
1. Open the IO Flow's Property pages.
2. Click the Items tab.
3. In the Show Associated list, select Realization.
4. Click the Link button.
5. In the Links Editor, select the check boxes associated with the required Association, Control Flow, Exception Handler, IO Flow and Object Flow items, and then click OK.