Closed loops scenarios in BW

Closed loop systems use feedback where a portion of the output is fed back to the input to reduce errors and improve stability. In BW world we can say that transformation of data that runs on top of same InfoProvider object (cube, aDSO) are the closed loops. In nutshell data transformation it writes data back to its source.

Such a scenarios are used quite often in BW. One of example can be a calculation of additional key figures on top of those that were calculated during a load from different objects underneath the target object.

Topic of closed loops appears when there is a migration to BW4/HANA. Normally during the migration BW objects that are not supported in BW/4 anymore need to be converted to the new objects. BW/4 requires these closed loops data loads and associated DTPs to be remodeled. In the BW/4 some write optimized aDSO needs to be part of the flow.

In order to help with the remodeling there are few tools (ABAP programs) provided by SAP:

RSB4H_REBUILD_CLOSED_LOOP_DTPS    Rebuild closed loop DTPs

RSBK_FIND_CLOSED_LOOP_DTPS            Identification of closed loops

 

PS: Closed loops data loads are sometimes also called as Ring Loads.

More information:

3013897 - Closed Loop DTPs in the context of BW4/HANA Conversion

3019023 - Transfer Tool DTP & RSSM (41) - Report to rebuild closed loop DTPs