Before we learn more about SAP BI Architecture, lets learn about
Conceptual Layers of Data Warehousing with BI
Persistent Staging Area
The data extracted from the Source Systems first enters into the Persistent Staging Area. The data at this layer is the raw data which is in unchanged form. The data is consolidated and cleansed only in the next layers.
Staging area is a temporary table that holds the data and connects to work area or fact tables. In the absence of staging area the data load will have to go from the OLTP system to the OLAP system directly which hamper the performance of OLTP system.
Data Warehouse Layer (DWH Layer)
Data from the Persistent Staging Area is loaded into the DataWareHouse Layer. It has Corporate information repository. Data in this layer is stored for a longer period.i.e,Entire History data (for example, last 5 years data) is stored here in this layer.No aggregation of reporting-relevant data;the granularity of the data stored in this layer is at line-item (detailed) level.
Operational Data Store Layer
Data is loaded to an Operational Data Store Layer very frequently on a continuous basis from the source systems. Hence the data in this layer contains all the changes to the data that was done throughout the day. Data from Operational data store later can be loaded to the Datawarehouse layer at particular timings (say end of the day) to update the date in Datawarehouse Layer. This Operational Data Store Layer can also be used in case of any emergencies when the data in the datawarehouse and datamart layers are lost. In such situations data can be loaded from the Operational Data Store layer to the Data Warehouse Layer and Data Mart Layer. ODS is not based on star schema model but they are in a flat files format.
Architected Data Mart Layer
Architected Data Mart Layer also known as Infocube. It is designed to store summarized and aggregated Data for long period of time. Data from the Data Warehouse Layer is loaded into the Architected Data Mart Layer. It is used in Analysis and reporting. The data is at a high level relevant for creating reports displaying these data. Data manipulation with business logic is done at this layer. It consists of a central fact table(Key Figures) surrounded by several dimension tables, it is used to support BW queries
Key Components of SAP BI System
Business Intelligence is a core component of SAP NetWeaver. The figure below shows the key components of a BI system.
- Data warehousing – This is mainly to Extract, Transform and Load data from Source systems.
- BI platform – The BI platform layer contains BI services to support complex analysis tasks and functions. It contains the Analytic Engine, which processes the data requested through BEx analysis navigations. Its interface allows entry and manipulation of data as part of BI Integrated Planning. It also has special analysis tools such as the Analysis Process Designer (APD) and the Data Mining which provide analysts at your company with the tools to merge, mine, pre-process, store, and analyse data.
- BI Suite – These tools helps in creating reports for analysis purpose.It contains the Business Explorer (BEx) which provides flexible reporting and analysis tools.
The following areas in the Business Explorer can be used for Data Analyses:
- BEx Analyser (Microsoft Excel-based analysis tool with pivot-table-like features)
- BEx Web Analyser (Web-based analysis tool with pivot-table-like features)
- BEx Web Application Designer (customer-defined and SAP BI Content provided)
- BEx Report Designer (highly formatted Web output)
SAP BI/BW Architecture
BI has three tier architecture:
Database Server: Where data is physically stored.( ODS, PSA, Infocube and metadata repository).
Application Server: The application server is based on the OLAP processor. It is used to retrieve data stored in the database server.
Presentation Server: Manages reporting and data access.
- Data is extracted from the Source Systems.
- Data is staged at the Persistent Storage Area(PSA). This holds Source like data.
- Data is cleansed, loaded and stored in Data Store Object.
- Data is viewed at multiple dimensions in the Infocube.
- Data is available by the OLAP processor to the Business Explorer to display data as per Analysis requirements of the Business.
- Data can be made available to SAP/Non-SAP, Data Marts by the Open Hub Service.( InfoSpoke).