Navigate to Administration > Actions as a organization user.
Click the Assign To Events link in the row for the action you wish to assign. You will be taken to the Assign Action Profile page.
For each device in the list, checking the All Message Types check box will assign the action to all the tests on the selected device(s).
For each device in the list, checking the Select Message Types check box will display another window for you to individually select the test(s) to which you want the action assigned.
Click Assign Action at the bottom of the page to save your changes.