Oracle offline backup once a week would mean that you have to
recover up to 7 days with redo logs. If you have a backup window
of 3 hours you will also need 3 hours for restore and i assume
at least additional 5 to 6 hours for recovery of a whole week!

We use BACKINT (it's a backup interface defined by SAP to be
connected to SAPDBA) to do daily online backups and one
offline backup per week of our SAP Oracle database.

But ADSM has a separate Oracle connect agent which provides
the same feature.

regards

Reinhold Wagner, Zeuna Staerker GmbH & Co. KG