Assigning Interfaces 
You can assign one or more outbound or inbound interfaces to an action. These can be message interfaces, RFCs, or IDocs.
For more information about the different interface object types, see the Introduction to Interface Development section of this documentation.
Note the following restrictions when assigning interfaces:
· The software component version of the interface must be the same software component version as the action. The name of the interface and the action do not have to be the same.
· When assigning an inbound interface, it must be an inbound message interface, an RFC, or an IDoc.
· When assigning an outbound interface, it must be an outbound message interface, an RFC, or an IDoc.
You have called the action editor.
...
1. Depending on whether you want to assign an inbound or an outbound interface to the action, choose either Inbound Interfaces or Outbound Interfaces.
2.
Choose
Insert Empty Line Below Line Selected (
).
3.
You can call
the search help in the inserted line. To do so, choose the search help icon
(
) at the end of the table
line. In the dialog Select Interface, select the interface you want to
use.

Only those interfaces that match the criteria above are displayed in the dialog.
4.
Select the
interface you want to use and choose OK (
) to confirm.

You also have the option of assigning the action a message interface that has not yet been defined in the Integration Builder. To do so, carry out steps 1 and 2 above. In step 3, enter the name of the message interface manually in the corresponding field. You can also specify an appropriate namespace, if necessary.
This option is supported by the top-down approach: You have the option of modeling the interface initially as just part of an action, without having to define it as a development object in the Integration Builder first.
This can be done in the Integration Builder at a
later stage. In the action editor, position the cursor on the interface in
question and choose New (
) from the context menu. A message interface is
then created with the name and the namespace being taken from the action
editor. You can now define the properties of the interfaces.

This is only possible for message interfaces and not RFCs or IDocs.

Note that you can change the direction and mode of an interface during its design, but any changes you make will not be taken into account in the action editor or Business Scenario editor. These can therefore lead to inconsistencies.
The interface is assigned to the action and the name of the interface is displayed in the Inbound Interface or Outbound Interface area of the action editor.