Best way to transfer data from one R/3 system to another
Is there a way better way of transferring transactional data from one R/3 system system (STG) to another R/3 system (QA) -- other than using custom ABAP programs to extract document (FI, HR etc.) data from (STG) and then using standard SAP BAPI/IDOC/ALE/SXDA/CATT techniques to post documents into the QA system?
So my advice is: Search a proper IDoc for the data you need to send, then check the transaction that generates the data if there is away to trigger the IDoc conveniently.
The BAPI approach has some appeal in this context, as it does not store temporary data (like the IDoc in EDIDC/EDID4). So it is certainly the most preferred way, but it needs some development.