Task concurrency model
A task describes a group of objects having a common thread of control. You map tasks to classes, or boards defined in the System Architecture Model.
Use the 
button on the Concurrency Diagram tab to add a task to the diagram, or you can drag and drop a task from the dictionary.
button on the Concurrency Diagram tab to add a task to the diagram, or you can drag and drop a task from the dictionary.When you have added a task, you can change it both via the diagram using the task Property pages and the context menu.
If you want to map your task to a class use the drop-down list box in the Options tab of the Property pages. Alternatively you can link the task and class in the dictionary. See Class Modeling for details on setting up a class.
To associate a task with a board:
1. Right-click the Task, and select > .
2. In the Types list, select Boards.
3. In the left pane, select the appropriate folder or Package to display the required Board.
4. In the middle or right pane, select the check box associated with the Board you want to link.
5. Click OK.
The task and board are linked in the expanded view of the relationships pane.