Hi Sanjay,
There are mainly following changes in SD
- De-normalisation of SD tables (Note : 2198647 - S/4 HANA: Data Model Changes in SD)
- Introduction of business partner (https://websmp103.sap-ag.de/~sapidp/012002523100007374172016E.pdf)
- Output change in billing (2228611 - Output Management in SAP S/4HANA)
- Inventory valuation in multiple currencies with mandatory material ledger (Material ledger embedded in S/4 HANA - Benefits and challenges)
- WM : ECC WM is present in S4H 1511, but it will be replaced by EWM (SAP’s road map for Supply chain solutions with S/4 HANA and expected benefits of unification)
Also refer S/4 HANA and its differences with ECC | SCN and The TOP Simplification List Items
Regards,
Mrinal