Main menu for workflow is SWLD
The workflow events are coupled and enabled via transaction SWETYPEV (rel 4.6++; earlier releases edit table SWETYPECOU with SM30).
A workflow handler must comply with a rigid interface. To create an own handler for an event, you can copy PUR_ORDER_CREATE_VIA_SD_EVENT as a template.
To check out what events are fired by your application, you can check the event trace (transactions SWEL and SWELS).
For sales orders there is an event predefined: ALECREATED. In the event coupling SWETYPEV the processing by PUR_ORDER_CREATE_VIA_SD_EVENT is already defined but not activated. You can use this scenario as example for your works.
If the IDoc is updated by a transaction that does not fire events, you can indirectly trigger an arbitrary workflow via the change documents which fire their own events from within the function CHANGEDOCUMENT_CLOSE.
More details can be found in "The R/3 Guide to EDI and Interfaces" or at http://logosworld.com.
This was first published in June 2003