LSA approach with standardized design and structured data area into multiple layers is still the reference architecture to design consistent, complete, comprehensive DWH for Solvay.
LSA Principles applied by Solvay for his BW are still relevant in a BW running on HANA context, this architecture focus on Performance and Governance: Data Quality, DataOnwnership, Service Level…
However, as volume of information is particularly important for SAP HANA (RAM Based approach) and as HANA brings BW new performances concept and capacibilities current BW Modeling must be adapted to get use of HANA BW features:
LSA++ is the next logical step from LSA (Layered Scalable Architecture) based on the new technical possibilities provided by SAP HANA Database capabilities.
One of the major areas is the possible lower number of layers (simplification), but also the different access to the data.
LSA++ provides increased modelling flexibility, mixing BW and SAP HANA studio capabilities, decreasing load and activation time. Approaches which were technically not possible before are now possible with LSA++.
With BW powered by HANA completely new options became available from an LSA perspective with regard to how to implement a BW EDW. The in-memory capabilities of HANA enable BW to expand it's focus to a more open logical architecture with less persistence and even more flexibility and scalability. The LSA++ is the reference architecture for implementing an EDW with BW powered by HANA. With LSA++ for BW on HANA there are huge opportunities developing the BW EDW further into a holistic data framework for consistent BI on the EDW, operational and agile BI.
Two challenges are building Time to Market Application and providing Real Time data where needed, like in operational reporting area.
The following objects are to be used in place of the old objects types
1. Advanced Data Store Object (ADSO): It is the central modeling object in SAP BW. ADSO is poised to replace all physical InfoProviders that used to store data in older versions of BW (likes of DSO, InfoCubes).
2. Composite Provider: Since the release of SP8 and BW 7.5 SP1, it has re-evolve completely to support the new modeling options. Composite Provider is an InfoProvider that combines data from both worlds (BW native models and HANA based views).
3. Open ODS Views: it enables one to define BW models for objects like database tables, database views, or BW DataSources (for direct access). It provides flexible integration without the need to create InfoObjects. The biggest benefit is its ability to consume external data sources into BW without the need for a separate BW persistence for the data.
Big Picture of LSA ++ implementation: A mix Modelling HANA Studio Approach is implemented.
Golden rules for modeling and data lineage are:
Hence for any new project or important maintenance developments, the following level are to be used:
The following infoareas & Hana packages are to be created
Level 1 : RAW Data acquisition = Propagation layer
DSO and nothing are done on the transformation between Datasource and this DSO (1 to 1 and no business transformation rules) because it could be the source for several project
This level can be build upon field (and not infoobjects)
Level 2 : Enterprise datawarehouse = Business Layer
DSO or several level of DSO if the transformation are complex and if data is to be historised
Level 3 : Virtual layer – application datamarts & application reporting
Hana views / Open ODS view
Composite providers (based on union of DSO or Hana views)
Queries based on composite providers or Hana views based on queries (in exceptional cases)
Level 4 : Open Hub Destination
In this level all open hub destination linked with composites , ADSO or queries based related to the infoarea will be stored.