WBS Updates in R/3 not Key in BW

Question

In R3, POSID can be changed without impact to the WBS in R3, but with great impact to the WBS in BW, which understands the new POSID as a new WBS element. Only a full delete/load of both the WBS Master Data and Transaction Data into BW will keep the BW and R3 WBS records in full sync. This is not practical in the BW Production environment. Also, it would not be known when a user changes the POSID in R3, so full loads would need to be done daily to insure that all changes are captured. Again, not practical in Production.
Although costs are often posted to Networks rather than to WBS elements, especially upper level WBS elements, “roll-up” of costs under a WBS is often a very common form of reporting in BW, especially for Project Managers. These WBS "roll-up" reports in BW would report costs on the previous POSID unless full replace of WBS Master and Transaction records were done between BW Report run times.
Has anyone else run into this problem? One recommendation would be to change the current process with custom development. The "lowest impact" options in my opinion would be:
Block the ability of the users to change the WBS POSID on the R3 side.
Change the BW WBS Primary key from POSID to a concatenation of POSID/PSPNR, and create a Rule during BW WBS Extraction to check if the POSID for an existing PSPNR has changed – if yes, replace the POSID for the existing PSPNR with the new POSID name.
Any thoughts?

Answer 1

Here is a note from SAP on the WBS issue. According to Colm O'shea (SAP support) they are going to try and put a fix in the next plug-in upgrade. 
New and extended interfaces for integrating SAP R/3, SAP R/3 Enterprise, and SAP ERP Central Component (SAP ECC) will no longer be delivered with their own add-on (SAP R/3 Plug-In).  As of SAP ECC 6.0, they will be contained directly in SAP ECC.
PI 2004.1 is therefore the final separate delivered SAP R/3 Plug-In release.
This means that:
SAP ECC 6.0 and subsequent releases will automatically contain all integration interfaces that so far have been contained in the SAP R/3 Plug-In and that ensured the technical integration with other SAP Components.
Customers who run SAP R/3 4.6C, SAP R/3 Enterprise 47x100 and 47x200, and SAP ECC 5.0 will receive additional integration interfaces in a Support Package for PI 2004.1 once a year. The delivery of this Support Package will be synchronized with that of mySAP Business Suite. The 2005 delivery is in November as part of Support Package 10. Information about the delievery from 2006 onwards are take place here
This rule applies only for customers with a SAP R/3 Plug-In release PI 2004.1. Customers with PI 2003.1 or older must first upgrade to PI 2004.1 or SAP ECC 6.0.
No new interfaces will be provided for integration between new SAP component releases and SAP R/3 3.1I to 4.6B.
Number              739182
Version             2 vom 25.05.2004
Status              Released for Customer
Set on             ,25.05.2004
Language            EN
Mastersprache       DE
Short text          PSBW: Renaming PS objects
Responsible         SAP AG
Component           BW-BCT-PS
                    Project System
Long text
Symptom
In the project system, you can rename the following objects: project
definition, WBS element, network and network activity. In this case,
only the external identifier of the objects is changed. The internal
identifier (object number and Guid) is retained.
In the BW content of the PS, the external identifier of the objects is
stored in the cubes.
If the objects in the source system are now renamed, the reference of
the transaction data already loaded for this object disappears in BW,
since this refers to the old external identifier.
Other terms
PSBW, 0PS_C01, 0PS_C02, 0PS_C03, 0PS_C04
Reason and Prerequisites
This is due to a design problem.
Solution
Currently the only solution is to load master data and transaction data
again into BW.
You can use the following authorizations to prevent renaming of the
external identifier in the source system (in this case, activity '45' is
responsible for renaming the external identifier):
    o  Project definition: C_PROJ_... authorization object
    o  WBS element: C_PRPS_... authorization object