Testing Failed Updates 
Testing is useful in the following cases:
You suspect that a temporary problem occurred, or you have corrected the update problem, and want to test whether the update now works. A successful test indicates that the problem has been resolved.
You would like to try to re-create the error that the update failure generated. If the test fails, the system displays the error message with which the update processing was terminated. Click on the message to display online help.
Note
An error message displayed by the test may or may not be the same as the original message, depending again upon conditions in the system.
Procedure
On the Update Requests screen, position the cursor on the record you want to test, and then choose 
Update records 
Single test 
, or 
(Single Test) to test the canceled update record.
Caution
Do not test any updates that are waiting to be processed or are currently being processed (status = init, auto or run) because processing could be canceled by the test.
Result
The test processes the selected function module, and then outputs either a success message (in the status bar) confirming that the update was successful, or an error message indicating that the update was canceled.
The test does not make any changes to the database. More precisely, the test makes database changes but rolls them back automatically when the update processing is completed or aborted.
If the test was successful, you can repost the canceled updates (Process Updates Manually).