Sharath
There are two ways you can integrate CRM TPM and APO DP.
One approach is using the BAPI BAPI_PRMSRVAPS_SAVEMULTI to update individual promotions in to DP. This requires use of the promotion planning functionality of DP. The other approach is to integrate using BI as an interface.
One advantage of the BAPI/ promotion planning approach is that you can see individual promotions in DP. Also, the promotion can have a set of attributes (such as say Salesperson) that are available in the planning book (without these attributes being part of CVC or navigational attributes). You can drill down into the promotion key figure and see the detailed promotion quantities behind it. You can use DP disaggregation functionality to receive promotions at different aggregation levels.
In spite of all these advantages, I would use the promotion planning functionality with caution. Promotion planning introduces more complexity into your DP solution. There are some system restrictions of how promotion planning interacts with other DP functionality. Review the SAP implementation recommendations for your release for details. For example, promotion bases can only use characteristics but not navigational attributes.
The BI interface may be a simpler approach. In either case, the major complexity of integration is managing the planning levels/ hierarchies that are typically different in TPM and DP.
Rishi Menon