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Launch SECATT transaction.
Select Select the System Data radio button.
Enter a name for your System Data.
Click on Create Object.
On the Attributes tab, enter your System Data name as Title.
Switch to to the System Data tab.
Assign all remote systems ( with their RFC connections ) on which you would like to execute your Test Configurations. If you will only execute run it locally, entry with system "NONE" is enough.
Save your System Data.