Introduction to SAP NetWeaver Business Warehouse
Why DW/BI System?
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The goal behind the implementation of ERP
systems and other software tools is the cost reduction, and automation of
processes in individual business areas
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The result is that these ERP systems, CRM
systems, banking and credit card systems, etc. have exponentially increased
data volumes needing analysis
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Also, the ever-increasing globalization and, the
increasing decentralization of organizations has created the need to recognize
market trends and to collect information about competitors
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Decision makers in modern, globally operating
enterprises frequently realize that their survival depends on the effective use
of this information
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Unfortunately this information is often spread
across many systems and sometimes many countries, thus making effective use of
information extremely difficult
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This is precisely the challenge that modern
Business Intelligence systems attempt to meet
Evolution of SAP NetWeaver Business Warehouse
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BI/BW is warehouse tool developed by SAP
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First version was BW 1.2 (Business Warehouse), 1998
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BW 2.0 (Business
Warehouse), 2000
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BW 3.x/3.5 (Business Warehouse), 2004
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BI 7.x/7.0 (Business Intelegency), 2005
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BW 7.3 (Business Warehouse), 2010
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BW 7.3 (SP5)
(Business Warehouse ) HANA Enabled System, 2012
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Up till version BI 7.x most BI systems used
Oracle as a back end DBMS but with BW 7.3 (SP5) you have the option to deploy
your BI system with SAP proprietary in-memory database HANA
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So DW/BI/BW is one of the same thing
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However, there is major changes b/w version 3.x
and 7.x, specially the data flow has entirely changed b/w 3.x and 7.x
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We still need to learn the data flow of 3.x,
because SAP has pre-defined most of the contents called BI Content (InfoCubes,
Transformation, DataSources etc.)
BI Contents
BI Contents
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SAP has vast experience in business process
automation of various sectors, industries and businesses, and they found some
commonly used reports e.g. in Financial Organizations out of 10 reports 6 of
them is used commonly like yearly
reports so on generic basis SAP has given us 60% of the system pre-defined
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These contents are delivered to us in BI Content
in the form of delivered versions
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If the content satisfies your need you just have
to activate it to make it available for usage
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Otherwise you can customize it according to your
needs which is termed as Enhancements
Difference between OLTP
(Transactional) and OLAP (BW) Systems
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Online Transaction Processing (OLTP) systems
generates data like applications used by ATM Machines, Cashier machine in
grocery shop
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Consider a business process scenario in bank
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Ajmal want to open an account in bank, info
needed to create an account are Account ID, Name, Address, Contact No, DOB, …
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Using Account ID assigned to Ajmal, he can
perform transaction like deposits, withdrawals, fund transfers and online
purchases etc.
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This daily business process of bank generates
data, as illustrated in figure on next slide
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This daily business data is classified as Master
data and Transaction data
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Master data is a data that didn’t change for a
long period of time e.g. Account ID, Name, Address or Contact No
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Transaction data is data that change frequently
e.g. withdrawal made by ATM or deposit made by PC of bank cashier
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The sole purpose of OLTP system is that business
process must not stop, it must work efficiently and must be available for 24x7
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Reports are usually made on monthly, quarterly,
half yearly or yearly bases
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If we generate reports on huge data using
transfer rules, calculation etc. will put load on OLTP systems
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If due to this load transactions stop, i.e. if cashier is not able to deposit money,
means loss in business
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Therefore; to avoid performance bottlenecks in
OLTP systems this data will be transferred to OLAP (BI) system
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During transfer this data is cleansed or
harmonized using transfer rules for better read access
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Thus OLAP system can’t generate data, it rely on
source system (OLTP) for data
Benefits of OLAP System
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Query performance is increased as OLTP system is
free to perform transactions
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Historical reports are possible on OLAP systems;
because performance of OLTP applications depends on size of database, to
increase performance of OLTP system organization only maintain 1 month, 6
months or 1 year data on OLTP system, while the old data is archived in BI
system for historical reporting
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Analytical reports
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Analytical reports involves drill downs which
effects performance of OLTP systems
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E.g. consider a company has business in
Peshawar, Lahore and Karachi, after checking the sale of Pakistan report, it’s
observed that Peshawar is performing low business, to see further details of
Peshawar, the user will drill down Peshawar for more information
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BI contents allow developer not to start from
scratch
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60% system is already defined in the form BI
contents
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In BI contents
small changes can be made to objects (InfoProviders, DataSource etc.)
through enhancements which reduces development time
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Centralized repository
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Refer to the business example in point 3
(analytical reports) if this business don’t have OLAP system on top of three
individual OLTP systems, business analyst will have to approach three
individual databases for reporting, thus OLAP system acts as single point of
contact for an organization reporting need
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BEx independent reporting tool, with a basic
training to user a user can develop his own simple reports
Components of SAP NetWeaver BW System
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Figure shows the components of SAP NW BW system
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Source
System
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Source system is system which provide data to BW
system
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Figure illustrates different type of source
systems and their connection types supported by SAP NW BW
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DB Connect connection type is used
to connect to relational data sources
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UD Connect type connection is used to
connect to multi-dimensional data sources as well as relational data sources
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BI Service API is used to connect to SAP
source systems like SAP ERP, SAP CRM etc.
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File Interface is used to connect to flat file source system
like csv file
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Web Service is used to connect to online
systems e.g. to access order details from online store
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BAPI is used for legacy system, before
NetWeaver 2007 we were using 3rd
party ETL tools for connection, after NW 2007 with the help of ABAPers using
BAPI we extract data from legacy system
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These connections are maintained by admin
modules i.e. BASIS team
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95% of the time you will come across flat file
and sap source systems
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Data
Source (PSA)
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DataSource(PSA) a first layer in BW system which
stage the raw data from source system
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DataSources are BI objects used to extract and
stage data from source systems, the following
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Persistent Staging Area (PSA) is transparent
database table in which requested data is stored
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Depending
upon how you want to store data e.g. aggregated, detail level and what type of
data you are loading e.g. transactional or master you select different data
targets like ODS, VirtualProvider, InfoObjects etc.) which are termed as
InfoProviders
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Metadata
and documents on the left store data about your development status e.g. objects
you developed its states etc.
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Open hub
services allows to load data from BW system to other systems
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To pass
data from DataSource to a specific InfoProvider we perform a transformation i.e.
implementing business logic, calculations etc.
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Once data
is available in InfoProvider we can use the analytical services like reporting
etc.
Data Flow / Extract Transform and
Load (ETL)
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The ETL process or data flow is a list of steps
that raw (source) data must follow to be extracted, transformed, and loaded
into targets in the BI system
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The figure on next page illustrates the data
flow of BW 7.x version
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InfoPackage
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It is the scheduler object to load raw data from
source system to DataSource (PSA)
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InfoPackage also defines selection filters,
parallel processing, date of extraction etc.
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Transformation
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Transformation is set of rules based on which
data be loaded
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Data
Transfer Process (DTP)
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After the InfoPackage has extracted and saved
the data into PSA, you must execute DTP
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DTP reads data from PSA or another data target,
transform it, and supplies the cleansed data to the appropriate data target
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Process
Chains
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To extract data from source system and load it
into data target on regular basis, SAP BW offers a tool called Process Chains
that automates this activity
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