Hi,
You may designed proper data flow.
So now you need to load update data into bw.
fine.
Assume this is your data flow.
Data source(ECC)-----> PSA---> info cube/dso.
Please check and perform below steps.
1. So now create or use full load info pack and load data to PSA.
2. Load PSA data to target by using DTP(set as delta mode)
3. Create info pack, use settings - init - without data transfer and run it.
4. Later create delta info pack.
5. Do some chanegs at source side.
6. Check at source side RSA7, if you see total column count number > 0 against to your data source, then
7. you can run your delta info pack.
8. Later run your delta dtp.
About genric data source delta settings please search from google and help yourself.
Thanks