Friday, September 25, 2020

Converting BW system to BW/4HANA

As SAP NetWeaver will be sunsetting at some point of time (see details here: Life after life of SAP NetWeaver and Business Suite/ECC) same applies for one of the NetWeaver core component - BW.

SAP BW/4HANA positioned as SAP’s next generation data warehouse solution will be in nutshell replacing the BW. Needless to say that the BW4 is not a legal successor of BW rather it should be seen as a new product.

Customers are free to decide which way they choose to get to the BW4 level. In one of my previous posts Tools for migrating to SAP BW/4HANA (B4H) I wrote a little about the tools that are used for the conversion. In this posts I go a bit deeper into the tools that are available there.  In nutshell there are 5 options for the conversion:


1 New Installation - So called greenfield installation is nothing else just to starts with implementation from scratch. This involves whole implementation cycle, like gathering requirements, implementation, testing, go live, support etc. The tools that would be used here do not really have a sense, as we are not converting any existing system to the BW4. With an exception of a transport certain objects from the existing SAP BW system – see point no 4 below.

This type of installation (not conversion in this case) can be start from t-code STC01 (Task Manager for technical Configuration) by running task list called SAP_BW4_SETUP_SIMPLE. Basically, an initial setup of a newly installed SAP BW/4HANA system can be executed via the task list. Here are some of the included setup: activate web services for BW Modeling Tools, Maintain Allowed Characters in SAP BW/4HANA, creating RFC destination for After-Import Handling of Client-Dependent BW Objects (RSTPRFC), maintaining Query Executor Setting for Eclipse Query Designer and/or Workspace Query Designer, BW/4 Launchpad Setup, activating InA Services for SAP Analytics Cloud integration.


2 In-place Conversion - So called full system conversion means BW 75 system is turned to SAP BW/4HANA system. The new (converted) system has same SID as original one. It is conversion without reimplementation type of the conversion. The original BW objects are within step-by-step approach converted. In-place means transfer of classic objects types into their HANA-optimized counterparts. Downside is that original system needs to be on release Minimum start release SAP BW 7.5 SP 5 (recommended at SP12 and best for SAC is to be on SP15-16) powered by SAP HANA.

“SAP BW/4HANA Starter Add-on” is prerequisite for In-Place Conversions. The add-in is technically following software component:

BW4HANA     100     0001   SAPK-10001INBW4HANA    SAP BW/4HANA Starter Add-On

Within the add-on there is a SAP BW/4HANA Transfer Cockpit (t-code RSB4HCONV, prog RS_B4HANA_CONVERSION_CONTROL, there was a predecessor to this: RS_B4HANA_CHECK_ENABLE that is now obsolete) available where all the work is done. The Transfer Cockpit is divided to Prepare (includes pre-check tool, sizing report, code scan tool, clean-up reports, and initial run of authorization transfer) and Realization phase (includes scope transfer tool, delta run of authorization transfer, and change of operation mode).

Within the add-on installation, the system can be set to the following modes: BW Mode (add-on installed and particular BW models/flows/scenarios are being converted) -> Compatibility Mode (manual converting work is finished, BEx Query Designer is disabled, and incompatible scenarios still can run) -> B4H Mode -> Ready for Conversion (system can be converted).

The Transfer Cockpit also calls a starter of B4H Transfer Tool (t-code RSB4HTRF, program RS_B4HANA_TRF). 

In case of one chose, In-Place an ABAP program RS_B4HANA_INPLACE is called. In case of Remote a call of CL_CNVLTRL_BW4H_GEN_INFO =>load_bw4rc is performed. Finally, in case of Shell ABAP program RS_B4HANA_SHELL is called. In most of the cases STC01 task list are called.


3 Remote Conversion - So called system carve out / brownfield. Similar to the In-place Conversion. It starts with SAP BW/4HANA as green field installation (new SID) and BW data models/flows and data itself from original BW are transported to the new BW data models in the new system. Classic BW objects like cubes, DSO and PSAs are replaced by BW4 objects aDSO and composite providers. Minimum start release is SAP BW 7.0 or higher on any DB.


4 Shell Conversion - So called Accelerated Greenfield. Again, it is similar to remote conversion but without data transfer. Means only the BW data models/flows are transferred not the data itself. No transactional neither master data is transferred. Minimum start release is SAP BW 7.0 or higher on any DB.

5 BW Landscape transformation - So called system consolidation. In case there is a need to consolidate several BW systems into one e.g. multiple SAP BW, or SAP BW on SAP HANA systems to become one global system. Method of system conversion is typically mix of one several ones. Typically one in-place conversion and one or more remote or shell conversions.


For all the types of conversion very first things is check the original BW system before conversion. To support this here it is “SAP BW Migration Cockpit for SAP HANA” (program ZBW_HANA_MIGRATION_COCKPIT) available (see Tools for migrating to SAP BW/4HANA (B4H)). 

Other tools that are available within SAP BW/4HANA Transfer Cockpit (t-code RSB4HCONV includes:

1. Maintain BW/4 Transfer Tool Statistics (ABAP program RSB4H_STAT_MAINTAIN) – It enables maintenance and display of the statistics for scope transfers.

2. Table RSB4H_RCRDCOUNT - Precheck phase collects data into this table about record count for BW/4 Transfer Tool.

3. Deletion of Technical Content RS_DELETE_TECHNICAL_CONTENT – Classic BW technical content (objects like 0TCA* and 0TCT*) including the SAP BW Administration Cockpit are not compatible with BW4. This is available at button called “Delete Technical Content” in the Transfer Cockpit.

4. Transfers of Standard Authorizations (ABAP Program RS_B4HTAU_CREATE_RUN) - User roles including standard SAP BW authorizations are converted by transporting the original roles. This is available at button called “Transfer Standard Authorization”.

5. BW/4 Code Scan (ABAP program RS_B4HANA_CODE_SCAN) – or so called custom ABAP code scan does a compatibility checks of custom code with BW/4. This is available at button called “Scan coding”.

6. Sizing report (ABAP program /SDF/HANA_BW_SIZING) - Determine DB size relevant for BW/4HANA Sizing. This is available at button called “Run Sizing Report”.

7. B4 HANA Readiness check (ABAP program RS_B4HANA_RC) – Shows progress of the conversion. This is available at button called “Show Logs”.

8. Execute Prechecks button runs different method calls with respect to different phases of conversion like:

cl_rs_b4hana_util=>n_c_switch-standard_bw (val 0)

cl_rs_b4hana_util=>n_c_switch-prepare   (val 1)

cl_rs_b4hana_util=>n_c_switch-b4hana   (val 2)

9. table BW4HANAADMIN - used to store current mode of BW conversion. The table is access via methods of class CL_RS_B4HANA_UTIL_ADDON. It stored values of below modes:BW4HANA_READY4CONVERSION, BW4HANA_STRICT, BW4HANA_TRANSFER.

More information:

SAP BW/4HANA (B4H) versions

Tools for migrating to SAP BW/4HANA (B4H)

Conversion Guide for SAP BW/4HANA2.0

1909597 - SAP BW Migration Cockpit for SAP HANA

2351381 - SAP BW/4HANA task lists

2358953 - SAP BW/4HANA Conversion: Preparation Tasks

2383530 - Conversion from SAP BW to SAP BW/4HANA

2930058 - FAQ - SAP BW/4 Conversions

2285440 - Technical prerequisites in BW for "SAP BW Edition for SAP HANA" add-on

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