SAP BW/4HANA Migration – Discover Prepare Phase – Part 2
This is a follow-on article (part 2) from the SAP BW/4HANA Migration – Discover / Prepare Phase – Part 1 which covered the execution of the pre-check in transaction RSB4HCONV for the Discover / Prepare Phase of a migration to SAP BW/4HANA.
This along with the follow-on article (part 3) will cover the detailed explanation of the generated pre-check log by transaction RSB4HCONV.
SAP BW/4HANA is a new, next generation data warehouse product from SAP that, like SAP S/4HANA, is optimized for the SAP HANA platform, including inheriting the high performance, simplicity, and agility of SAP HANA. SAP BW/4HANA delivers real time, enterprise wide analytics that minimize the movement of data and can connect all the data in an organization into a single, logical view, including new data types and sources. SAP BW/4HANA drastically reduces the number of data objects hence less maintenance and storage. All future innovations will take place in SAP BW/4HANA.
Discover / Prepare Phase and In Place System conversion
This article covers the discover / prepare phase which involves checking of the system for BW/4HANA compliance (gather information about objects and code that needs to be transferred or changed) and estimate the effort for the conversion project. This article is applicable for an in-place system conversion which is to migrate a current SAP BW system into a SAP BW/4HANA system. Using the Transfer Toolbox provided by SAP, the SID of the system can be kept (i.e. in-place conversion).
SAP supports the conversion by providing pre-checks that identify some important steps you need to take to ensure your existing BW system is compatible with BW/4HANA. We can use these pre-checks to find out what mandatory steps you must carry out before converting to SAP BW/4HANA. The results list the activities that need to be addressed before attempting the BW/4HANA conversion process.
The BW/4HANA pre-check is done by executing transaction RSB4HCONV. This program is available from BW 7.5 SP 7. Please note that the SAP BW/4HANA Starter Add-on is not required to execute this pre-check.
BW/4HANA Discover / Prepare Phase Objective
Identify the scope required to transition the current BW system to a BW/4HANA system.
Identify areas that are not supported for BW/4HANA (for example open hub destinations and CMOD) and review alternative solutions.
Identify opportunities for BW team to use the transfer tool provide by SAP to automatically convert ‘legacy’ objects to BW/4HANA compatible objects (for example Infocube -> ADSO).
Explanation of the Pre-check log (RSB4HCONV)
The following is the log generated after executing the pre-check.
Please note that the red icon represents a manual conversion activity is required and amber icon represents that a transfer tool is available to do this activity (please note the object conversion of the amber objects are still required before the system is compatible for BW4HANA).
As one of the goals of SAP BW/4HANA is to simplify processes, not all SAP NetWeaver based add-ons are supported by SAP BW/4HANA. Please refer to OSS note 2189708 to determine which add-ons are supported.
This highlights the general status of the compatibility of overall system for BW/4HANA migration.
Several standard authorizations objects used in SAP BW are not available in SAP BW/4HANA. The simplification of object types in SAP BW/4HANA has an impact on authorization objects. When converting a SAP BW system to SAP BW/4HANA, authorizations for object types that are not available in SAP BW/4HANA (like InfoCubes) have to be replaced by authorizations for corresponding object types (like DataStore Objects (advanced)). There is currently no automated check of profiles and roles available. Please refer to OSS note 2468657 for additional information.
Review of 3.x Objects
The 3.x data flow migration tool (transaction RSMIGRATE) is not available in SAP BW/4HANA.
The migration from 3.x to 7.x data flows must be performed (via transaction RSMIGRATE) before the SAP BW/4HANA Transfer Toolbox can be used to convert data flows and model to objects compatible with SAP BW/4HANA
BW/4HANA Transfer Tool (use transaction RSB4HTRF)
The BW/4HANA Transfer Tool is launched with transaction RSB4HTRF. This tool automatically transfers BW objects to BW/4HANA compatible objects. For example, Infocube -> ADSO.
The following is a list of BW objects that can be converted using this transfer tool (transaction RSB4HTRF).
1. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Infopackage
The persistent staging area service (PSA) and InfoPackages are not available in SAP BW/4HANA. Therefore, it is no longer possible to load data via InfoPackage.
In SAP BW/4HANA, a data transfer process (DTP) is the only object type to load data into the system. It can access all supported source system types directly without using a PSA.
The Transfer Tool will allow you to either skip the InfoPackage and create the DTP directly on the DataSource, or transfer the PSA to an DataStore object (advanced) and replace the InfoPackage by a DTP.
The following InfoPackages cannot be handled by the Transfer Tool:
InfoPackages for 3.x DataSources
InfoPackages for Read-time Data Acquisition
Push InfoPackage for Web Service Source Systems
Multiple Delta InfoPackages for File Source Systems which read different files for same DataSource.
Please refer to note 2464367 for more information.
2. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Multiprovider
The SAP BW MultiProvider object is not available in SAP BW/4HANA.
It is not possible to convert a MultiProvider to a Composite Provider when:
The setting “Accept Inconsistency During Compounding” is set to true.
Navigation attributes from InfoObjects based on HANA Model are mapped in a way, that they cannot be used as navigation attributes anymore.
During conversion, it might be necessary to perform an InfoObject mapping. This is necessary because the Composite Provider requires a consistent mapping of navigation attributes. Navigation attributes therefore always need to be mapped consistently with the characteristic that the navigation attribute belongs to.
Please refer to note 2444718 for more information.
3. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Datastore Object
The SAP BW DataStore Object (classic) is not available in SAP BW/4HANA.
Conversion of Datastore objects
Write-optimized ODSO will be transferred into ADSOs without activation.
Standard ODSOs will be transferred into ADSOs with activation and change log.
ODSO for direct update will be transferred into ADSOs for direct update.
The Transfer Tool will automatically replace
Process chain variant “Activate Data in DataStore Objects (classic)” with process chain variant “Activate Data in DataStore Objects (advanced)”.
Process chain variant “Deletion of Requests from Change Log of DSO (classic)” and “Deletion of Requests from Write-optimized DSO (classic)” with process chain variant “Clean Up Old Requests in DataStore Objects (advanced)”.
Please refer to note 2451013 for more information.
4. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Process Chain
With SAP BW/4HANA, several process types are no longer available or have to be adjusted.
The following are supported by the transfer tool.
Deletion of Requests from DataStore Objects (advanced) – replaced
Initial Fill of New Aggregates – removed.
Deletion of Requests from DataStore Objects (classic) – replaced
Compression of the InfoCube – replaced.
Complete Deletion of Data Target Contents – adjusted.
Delete Index – removed
Generate Index – removed
Execute InfoPackage – replaced
Activate Requests in DataStore Objects (classic) – replaced
Switch Real-time InfoCube / aDSO to Load/Plan Mode – adjusted
Deletion of PSA data – removed
Delete Overlapping Requests from InfoCube – replaced
Roll Up of Filled Aggregates/BWA Indexes – removed
Deletion of Requests from Write-Optimized DSO (classic) – replaced.
Please refer to note 2448086 for more information.
5. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Datasource
The SAP and BW Source Systems based on Service API (S-API) are not available in SAP BW/4HANA. SAP BW/4HANA does not connect to other SAP systems using the SAP Source System. If you want to transfer data from Extractors / DataSources (Service API) of an SAP system to SAP BW/4HANA, then you can configure a ODP Source System with the “SAP (Extractors) Context”.
Alternatively, you can transfer data from SAP source systems using other ODP contexts, like “BW” (also applies to SAP BW/4HANA source systems), “SLT Queue” (for real-time replication), or “ABAP CDS Views“ (for SAP S/4HANA source systems).
The BW/4HANA Transfer Tool will automatically copy your DataSources which load from as SAPI or BW source system to a corresponding ODP source system of context SAPI or BW, respectively.
It will also seamlessly clone the delta queues, so that no delta data is lost or loaded double, and no downtime in the source systems is required.
Any SAP Source Systems left, when executing the switch to “Ready for conversion mode”, will be automatically deleted.
6. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – DTP
When a cube or DSO gets converted, the underlying DTP gets updated automatically.
The following is a list of restrictions with DTP’s on BW/4HANA
DTP’s that use error handling are not available (no error stacks, no error stack maintenance and no error DTPs). “Data Transfer Intermediate Storage (DTIS)” is provided, which covers the DTP error stack functionality.
No distribution of data extracted from source systems to the PSA and from there to several target objects (extract once – deploy many).
Potential for out of memory situations when using the DTP feature “Semantic Groups“
“SAP HANA Execution” is not possible for DTPs and Transformations that use ODP DataSources as source objects.
DTPs of type “Real-time Data Acquisition” or “Direct Access” are not available in SAP BW/4HANA.
Please refer to note 2464541 for more information.
7. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Cube
The SAP BW InfoCube object is not available in SAP BW/4HANA.
Basic InfoCubes can be converted to a DataStore Object (advanced) (ADSO) with option “All characteristics are key, reporting on union of inbound and active table” using the BW4 Transfer Tool.
The Transfer Tool will automatically replace process chain variant “Compression of InfoCubes” with process chain variant “Clean Up Old Requests in DataStore objects (advanced)“.
ADSO expose navigation attributes for staging processes only. It is not possible to consume navigation attributes of an ADSO directly in the query.
InfoCubes of type VirtualProvider or HybridProvider cannot be converted.
The DataStore object (advanced) does not support “zero elimination” at present.
Near-line storage: InfoCubes with active archive cannot be converted at present
Please refer to note 2443489 for more information.
8. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – ADSO
Data Transfer Processes created before SAP BW release 7.5 SP 4 are storing request IDs in as meta data for each data load into DataStore objects (advanced). However, request IDs are not available in SAP BW/4HANA.
ADSO which include request IDs (old request management) in the meta data must be processed once using the Scope Transfer Tool to clean-up the meta data.
Please refer to note 2487023 for more information.
9. BW/4HANA Transfer Tool (use transaction RSB4HTRF) – Conversion Types
The currency translation types, unit conversion types, and key date derivations based on InfoSets must be adapted manually or deleted.
Unit conversion types based on classic DataStore objects can be converted to use DataStore objects (advanced) using the Transfer Tools.
Please refer to note 2443281 for more information.
This article (part 2) along with a follow-on article (part 3) provides a detailed explanation to the log generated by transaction RSB4HCONV.
Even if you’re not considering migrating to BW/4HANA now, it’s extremely important to start to review this conversion now due to the following factors
Simplification: Two objects (ADSO & Composite provider) for all LSA++ layers. Number of Modelling object types reduced from 10 to 4 (60% less)
Performance: ODP extraction performance benefits – for example the extraction reduction of a delta execution of the 0FI_GL_14 ODP is from 74% to 86% in PRD – (ODP—Performance-improvements-and-benefits)
BI Schedule: Parallel data loads to and from an ADSO is possible without any locking restrictions which will reduce the overall execution time of the BI schedules.
Innovations: All future SAP development innovations will take place on SAP BW/4HANA compatible objects.
BW/4HANA: The BW/4HANA is a new solution, it’s not an upgrade of BW 7.5.
BW 7.6: There is no BW 7.6. The last version of BW is 7.5.
Future Innovations: All future SAP development innovations will take place on SAP BW/4HANA.
BW 7.5 Support: The support maintenance on BW 7.5 will end on 31.12.2024.
BW/4HANA Ready: Getting ready for the actual migration to BW/4HANA in a controlled and organised approach. This phase of work is a substantial piece of work and needs to be completed in full before the actual migration of the system to BW/4HANA can happen.
Reporting: Report at any layer of the Data Warehouse with speed and flexibility including virtually combining data across layers.
Flexibility: Composite providers allow Info Providers to be combined using the JOIN operation allowing us to create new scenarios not possible before or if possible in the past would have very poor performance with standard techniques via Multiprovider or InfoSet
LSA++: Transition your LSA (Layered Scalable Architecture) to LSA++.
Reduce LSA/LSA++ Layer: Potentially remove the reporting layer and the existing transformation layer becomes the reporting Layer.
Reduction of objects and DB Size: By removing the reporting layer, the number of objects to support is reduced along with DB storage size.
Finally, it’s extremely important to understand that the conversion process of the objects does not mean that you must transition the BW system onto BW/4HANA. The conversion process can be executed on a standard BW system (For example BW 7.5 SP 11) without committing to move to BW/4HANA but has to be executed in each BW system!!