Hi Amol,
The DP being the forecasting module, generates the forecast or PIRs (planned independent requirements). These PIRs are then used as input for the operative planning (SNP/PPDS) in APO. The master data that exist in ECC (relevant to MRP); the same data is required in APO for this operative planning (alongwith the additional master data that only exist in APO). The master data required for DP in APO is the CVCs (Characteristic value combinations) only, not the ECC master data.
Hope this helps!
Regards,
Umesh