There are many events defined for each Business Object. But I find either none or just a few of these events for the business objects defined through the event linkages.
Only events that start a follow on process using a workflow, standard task or an FM or defined in event linkages. Not all entries available will be flagged as active. Some of these could be supplied as standard and you activate them as needed and may involve additional config steps. Some of them might have been active once and deactivated later.
I am assuming that all events for a business object must have been defined for a specific purpose and that they must be getting triggered/created somewhere.
Every object can have certain standard entries like Created, Changed etc. There could be object specific events also. There are standard SAP objects with no events defined at all. You can also extend an object with your own events. How you want to react to an event is specific to your business needs. Also, not all the events defined for an object are triggered/created. You may have to do it yourself with various tools provided by SAP. You can test what events get published for an object by activating event trace and taking the object thorough various stages.
a) Is there a way to get a where-used list for events?
One way is to look at the event linkages (txn SWETYPV) as you have already done. Another way is to txn SWU0 to simulate an event and see how the system would react to that event.
b) Are there some SAP-defined events that never get created?
Answered above.
ANd checkout this link
http://help.sap.com/saphelp_46c/helpdata/en/a5/3ec8534ac011d1894e0000e829fbbd/content.htm
Thanks,
Bluesky
