Migrating SAP Netweaver BW or SAP BW/4HANA models to SAP BW Bridge

Objectives

After completing this lesson, you will be able to:

  • Migrate SAP BW Content into SAP BW Bridge

Migrating SAP BW Content into SAP BW Bridge

Paths to SAP Datasphere, BW Bridge

Note
The terms migration, conversion, and transfer are sometimes not clearly defined and not strictly differentiated. In fact all of them are often used to describe the same scenario. In this course, we refer the following understanding:
  • Migration: Overall process of moving meta data (data models based on TLOGO objects) and sometimes even the related data (transaction data, master data) from one location to another, in our case from on-premise SAP BW or SAP BW/4HANA systems to SAP Datasphere, BW Bridge in the public cloud.
  • Conversion: Migration process including the transformation from obsolete TLOGO object types to up-to-date successor TLOGO types (for example, InfoCube in on-premise system is converted into ADSO in target system), normally sending systems like SAP BW 7.x on any database in general, or SAP BW 7.x on HANA data flows which still use the classic objects.
  • Transfer: Migration process without any TLOGO type conversion, valid for SAP BW/4HANA as sending systems or SAP BW 7.x on HANA data flows, which use the latest objects already.

For SAP BW systems on releases from 7.30 to 7.50 running on SAP HANA or any supported relational database and SAP BW/4HANA 2021, a Shell Migration can be performed to migrate classic on-premise content to SAP Datasphere, BW Bridge. Shell Migration migrates the metadata only. A Remote Migration, which migrates the master data and transactional data as well, is currently available as alternative.

First of all, a newly provisioned SAP BW bridge in SAP Datasphere is needed. Afterward, the SAP standard Transfer Cockpit can be used to migrate selected data models without data (Shell approach) or with data (Remote approach) into the SAP BW bridge tenant.

For the original system, the Transfer Cockpit was made available through SAP Notes for following support packages:

  • SAP NetWeaver BW 7.30 and 7.31: SP10+
  • SAP NetWeaver BW 7.40: SP12+
  • SAP NetWeaver BW 7.50: SP05+
  • SAP BW/4HANA 2021: SP01+

However, SAP highly recommends that you start a migration project using the latest support package. This will massively reduce the effort for SAP notes implementation. For example, a Remote approach would require more than 400 SAP notes to be implemented in a BW 7.30 SP10 system.

The Transfer Cockpit requires an up-to-date set of SAP notes to be applied in the relevant on-premise system(s). To validate this, SAP provides the so-called SAP BW Note Analyzer to analyze the relevant system(s) and to implement missing SAP notes.

SAP BW Bridge Readiness Check

SAP Readiness Check for SAP Datasphere, SAP BW bridge is a self-service toolset to assess the status of your existing SAP BW 7.x or SAP BW/4HANA system in preparation for a transfer to SAP Datasphere, SAP BW bridge. The existing Readiness Check framework for SAP BW/4HANA conversions was enhanced for SAP BW Bridge. Simply run the report RC_BW_COLLECT_ANALYSIS_DATA and change the Transformation Target to SAP Datasphere, SAP BW Bridge.SAP Readiness Check evaluates the compatibility of source systems, object types, add-ons, and custom code. You can download a comprehensive result list that enables you to understand respective effort and implications. This early insight means that you can scope and plan your transition project with a higher degree of accuracy.

Setting up Communication Scenarios

Regardless of which migration approach is chosen, it is an important prerequisite to properly set up the connectivity between the sender system and the receiving SAP BW Bridge system, as well as for the source systems involved. The RFC connection between the sender system and the receiver system is established using the Cloud Connector. SAP BW Bridge does not support SAP GUI. For this reason, you do not set up RFC connections in transaction SM59, but SAP provides a Fiori based interface, the SAP BW Bridge Cockpit for administrative and operational tasks in SAP BW Bridge. Here, you must maintain the communication users used for the remote communication and the communication systems, especially the sending system and the source systems. Then you need to define which communication system and which user can call which APIs (which scenarios) of BW Bridge including all related parameters. Such a combination is called communication arrangement.

The communication arrangement defines which system (communication system) and which user (communication user) can call which APIs (communication scenarios) including all related parameters. In the context of SAP BW Bridge, SAP provides the following default communication scenarios: SAP_COM_0692 for ODP-RFC source systems, SAP_COM_0886 fpr ODP-HTTP source systems such as S/4HANA cloud, SAP_COM_0691 for migrating meta data, SAP_COM_0818 for migrating data.

SAP provides standard communication scenarios, such as SAP_COM_692 to use a system as a source system for SAP BW Bridge. You need it before you can establish an ODP-RFC datasource and load data.For SHELL migrations, a communication arrangement based on the communication scenario SAP_COM_0691 (SAP BW Bridge – Migration Integration) is required.For REMOTE migrations, two communication arrangements based on the communication scenarios SAP_COM_0691 (SAP BW Bridge – Migration Integration) and SAP_COM_0818 (SAP BW Bridge – Data Migration Integration) are required.If you transfer data flows based on an SAP S/4HANA Cloud source system, the communication scenario SAP_COM_0886 (ODP HTTP source system integration) is available.

Note
A communication arrangement for ODP source system integration is not sufficient to execute a shell or remote conversion. Instead, the above mentioned communication scenarios are always needed in addition.

The Shell Migration Approach

For SAP BW systems on releases from 7.30 to 7.50 running on SAP HANA or Any-DB and SAP BW/4HANA 2021, a SHELL migration can be performed. For this approach, a newly provisioned SAP Datasphere, SAP BW bridge tenant is needed. The Transfer Cockpit in the sending on-premise system can be used to select dedicated data flows (BW applications) and migrate them without data into an SAP BW bridge tenant. In SAP BW Bridge, the data models will be converted into successor object types, if required. During this process, new technical names for ADSOs generated from InfoCubes or DSOs can be defined. The same applies for CompositeProviders that are generated from MultiProviders. This features relies on an RSADMIN parameter as described in SAP note 2911800 (shell migration: changing of object names).

After the transfer to the BW Bridge, the InfoProviders do not contain any data there. For loading the data, there are the following options:

  • Historical data can be loaded either from the SAP BW sender system of the original SAP source.
  • Current data can be loaded from the SAP source system.

SAP provides a well-defined process for a shell migration to SAP BW Bridge. This process can be structured into a preparation phase and a realization phase. This section gives an overview of the tools, and the activities involved in these phases.

1a) PREPARE Phase - Check all System Requirements

  • As described in the section before, it is recommended to update the sending BW system to the latest support package level and to leverage the SAP BW Note Analyzer to implement the most up-to-date SAP note corrections.
  • The connected SAP Sources should also be checked for updates based on the SAP BW Note Analyzer.
  • The BW Modeling Tools also require to be updated to the latest version. See SAP note 1944835 (SAP BW Modeling Tools – Delivery Schedule).
  • SAP does not provide a direct access from a frontend tool to the SAP BW bridge space and hence all reporting must be performed accessing SAP Datasphere. In the end, customers initially will have to rebuild their reporting in SAP Analytics Cloud (SAC) directly on SAP Datasphere.
  • It is also important to properly size the new SAP BW bridge tenant. Sizing is performed by program /SDF/HANA_BW_SIZING, which is provided and documented using SAP Note 2296290. This program has been enhanced with an option called Perform Bridge Sizing.

1b) Prepare Phase – Validate the simplification list.

To enable an optimal planning SAP provides the Simplification List for SAP Datasphere, SAP BW bridge. It provides the key information by object type or functional area about the simplifications in SAP BW Bridge. Each simplification item details the preparatory and follow-on steps that need to be considered for the conversion from a business and a technical point of view. Each item is available as an SAP Note that may contain additional information. You find this Simplification List attached as MS Excel document attached to SAP Note 3154420, Simplification List for SAP Datasphere, SAP BW Bridge).

  • Pre-Checks: SAP supports your migration project by providing pre-checks that identify some important steps you need to take to ensure your system is compatible with the migration process. Perform these checks before starting the realization phase to have enough time to solve any issues before starting the migration processes. Customers can use these pre-checks to find out what mandatory steps they must carry out before the migration. The pre-checks are delivered by SAP note 2575059 (SAP Readiness Check for SAP Datashere, SAP BW Bridge) and the xml-attachment that has to used with the SAP BW Note Analyzer.
  • Custom Code Check: To support customers in detecting custom code that needs to be adapted for the move to SAP BW bridge, SAP is providing a Code Scan Tool based on report RS_B4HANA_LOG_DISPLAY. For example, you can verify, if custom code embedded in transformations will be compatible with the SAP Datasphere, SAP BW bridge data structures and scope. For more information, see details related to custom code within SAP Help and in SAP Note 2462639, Interfaces and Customer-Specific ABAP Development.

2a) Realize Phase – system provisioning.

  • After the preparation of the on-premise system environment, the realization phase starts with adding the SAP BW Bridge tenant to the existing SAP Datasphere system. Details can be found in SAP Note 3134262 (Activation of BW Bridge Feature in an existing SAP Datasphere).
  • Beside this, a Cloud Connector is required, which is used for connecting the sending system for the shell migration as well as for connecting the source systems. A detailed documentation is available in the SAP Help for Getting Started With SAP Datasphere, SAP BW Bridge.
    1. Add the SAP Datasphere Cloud Subaccount in the Cloud Connector
    2. Add a Service Channel to the SAP BW Bridge Tenant in the Cloud Connector
    3. Create a Communication System in the SAP BW bridge Cockpit
    4. Create a Communication Arrangement in the SAP BW Bridge Cockpit
    5. Create an RFC Destination in the Sender System
    6. Create a Source System in BW Modeling Tools
  • Finally, at least one Software Component and one ABAP development package have to be created and the Transport management needs to be set up. In SAP BW bridge transport requests are required for creating objects as well as for the transfer with the SAP BW bridge Transfer Cockpit. Transport requests can be created in the BW Modeling Tools using the Transport Organizer view. For the transfer, the communication user (used in the communication arrangement above) must be added to the transport request. Ensure that the transport task is of type, Development/Correction. For best practices, check SAP Note 3130759.

2b) Realize Phase – Shell Transfer

This section describes how to transfer – and, if needed, convert – data models and data flows to HANA-optimized objects that are compatible with SAP Datasphere, SAP BW bridge by using the Transfer Tool. The Transfer Tool is launched with transaction RSB4HCONV and selecting the function Execute Scope Transfer. Alternatively, call transaction STC01, and run the task list SAP_BW4_TRANSFER_CLOUD_SHELL . The task list roughly goes through following activities, which are well documented in the conversion guide:

  1. Define the scope (based on the BW search function)
  2. Define object mapping and all dependent objects
  3. Validate scope including additional adjustments, if required
  4. Transfer Metadata from sending BW system to receiving SAP BW Bridge system incl. object conversion, if required

2c) Realize Phase – Post Transfer Tasks

The post transfer tasks a very dependent on the customer requirements. Typical tasks are to load the transferred InfoProviders either from the sending SAP BW system or from the original SAP source system. Additional tasks related to user management and authorizations might also be required, for example:

The Remote Migration Approach

Repeating a Migration for dedicated BW Objects

The normal approach is to migrate objects once only to SAP BW Bridge. This means future maintenance and changes need to be done in SAP BW Bridge. There is an exception from this concept and you can repeat the transfer of BW objects to apply changes of the sender system if its release is SAP BW/4HANA 2023.

  1. Run report RS_B4HANA_ALLOW_OBJECT_SYNCH and specify the object types to release them for overwriting. Alternatively you can allow overwriting of all object types.
  2. Make all required changes in the sender system.
  3. Use task list SAP_BW4_TRANSFER_CLOUD_SYNC (tr. STC01), then collect and transport the required objects again.

Transferring BW Queries

SAP BW Bridge does not support the usage the BW Queries or any related concepts (for example, Analysis Authorizations, data flow based on a Query Provider and so on). However, you can transfer existing BW Queries from the original on-premise SAP BW systems to the BW Bridge based on both transfer approaches (Shell or Remote) in order to import them later to SAP Datasphere and generate SAP Datasphere artifacts based on them. To be able to monitor which BW Queries are available for this process, SAP BW Bridge provides a little Fiori app in the Datasphere Modeling group of the BW Bridge cockpit to list those objects.

There are still some Query features that are not supported in SAP Datasphere and they bring additional effort and complexity for a migration towards SAP Datasphere. There is a strong focus to close these gaps. For more details, refer to the SAP Datasphere roadmap at roadmaps.sap.com.

There no 1:1 feature parity between SAP BW and SAP Datasphere (and there will never be). Both are based on a different foundations and follow independent data warehousing approaches. This means there are some areas which provide additional complexity on a journey from SAP BW or BW/4HANA on-premise to SAP BW Bridge and SAP Datasphere in the public Cloud. There are sophisticated tools available to transfer existing BW applications into SAP BW Bridge, but those are not applicable for some all kinds of objects and applications. For example, Open Hub Destinations, APD Analysis Processes or non-ODP Source Systems and their related data flows cannot be handled by them. For these and other components manual re-implementation efforts are expected. Some related major areas are the following:

  • BW OLAP Features: SAP Datasphere provides a new semantic layer combining data from several sources or layers and covers the same functionality as BW Queries.​ Many well-known Query features have already been implemented in the Analytic Model of SAP Datasphere, others have been identified and are listed as roadmap items (see figure above).
  • Reporting Layer: For SAP Datasphere, the recommended tool for all kind of data consumption (including planning) is SAP Analytics Cloud based on the rich semantics provided by SAP Datasphere Analytic Models. For existing SAP BW landscapes this means a considerable move from existing SAP BW landscapes which are often based on BW Queries consumed by classic Business Explorer tools, BusinessObjects clients like Crystal Reports, Lumira, WebIntelligence, and Analysis for Office or 3rd-party clients.
  • Planning applications need to be moved to SAP Analytics Cloud, see also following Blog post: https://blogs.sap.com/2023/03/09/accelerate-your-move-from-sap-bpc-to-sap-analytics-cloud-sac-for-planning-with-a-migration-guide/
  • Mixed Modeling based on external SAP HANA views: Mixed modeling in SAP BW is normally based on XS Classic, while the SAP HANA Cloud engine underlying SAP Datasphere is based on XS Advanced (XSA). Regarding the complexity and different kind of technologies, no migration tool support can be offered.
  • Open Hub Destinations are not supported in SAP BW Bridge. SAP Datasphere provides native export and data transport capabilities as an alternative. There is no migration tool support.
  • APD Analysis Processes: In SAP Datasphere you have the option to modernize the analysis process with a DataFlow artifact. There is no migration tool support.​
  • Source Systems: SAP Datasphere provides a great range of connectivity to data sources, in fact much larger than SAP BW. The focus of SAP BW bridge is to be a staging layer on classic SAP connections (mainly ODP_SAP), but other non-ODP interfaces like flat files and databases (HANA_*, DB-Connect, UD-Connect) need to be re-implemented in SAP Datasphere manually, there is no migration tool support.

References

For more details refer to following sources:

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