archive question

[Michael Marten]

Hello,
we just start to create a document for the archive/delete procedure of
workitems.
We want :
- to archive/delete workflows with different retention periods based on
the functionality
- use the "actual end date" as the start date plus the retention period
 
The selection screen (via txn SARA,object name WORKITEM) contains a  field
"Task ID".
Just a question about the relationships:
if a  workflow (which has his onw ID, actual end date and status) contains
(many)
workitems (of different types):
What do we have to define is this field "task ID"?
Is "WSxxxxxxxxx"  enough and all related workitems (who are based e.g. on
TSyyyyyyyyyy)  will be archived automatically?
 
Is there a good document for the archive/delete procedure?
 
Thanx, Michael