51 Bi Sap Bi Modeling

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SAP BW Data Modeling

SAP University AlliancesVersion 2.0Authors Klaus Freyburger

Peter Lehmann

© 2010 All Rights Reserved. SAP UA

Abstract:This chapter covers the basic aspects and concepts of data modeling with SAP Business Information Warehouse (SAP BW).

ProductSAP Netweaver BI 7.0

LevelUndergraduateBeginner

SAP BI Curriculum BI2-M2 SAP BW Data Modeling

SAP UA

• Overview• InfoObjects

– Key Figures– Characteristics

• InfoProviders– DataStore Objects

Agenda

Page 2© 2010 SAP AG

j– InfoCubes


SAP UA

SAP BW Architecture Overview


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SAP BW Data Modeling Architecture Objects and Data Structures



SAP UA

What is an InfoObject?

• InfoObjects are used to focus on business requirements.– Note:

• The original product name was “SAP Business InformationWarehouse.”

• The abbrevation “BIW” conflicted with another product name, so “BW” was chosen.


• InfoObjects are the “bricks” to build data structures inside SAP BW.– InfoObjects represent business objects from an end user’s

view.– The most important InfoObject types used for business analysis

are Characteristics and Key Figures.


SAP UA

InfoObject: Characteristics

• A Characteristic represents a business object (or concept, business term, business entity).– A Characteristic may have attributes which describes the

business object in more detail.– Example: InfoObject “Customer” is a characteristic with

attributes such as “Customer Number”, “ZIP Code”, “Region”,


, , g ,etc.

– The attributes “Customer Number”, “ZIP Code”, “Region”, etc. are also managed as Characteristics and may have their own attributes.

Note: What SAP calls a Characteristic is often referred to in the data warehouse community as a Dimension.

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SAP UA

InfoObject: Key Figures

• A Key Figure (or variable, measure) is oftenly used to document the performance of a business process over time.– It can be found in document records such as invoice, delivery

note, purchase order, or goods receipt.– Example: InfoObject “Revenue” or “Sales Amount”, etc.


• Note: InfoObjects are unique inside SAP BW, and they are used to build the data structures for analysis requirements.– Conceptually unique: the semantics (meaning) of an

InfoObject is uniquely defined system-wide inside SAP BW.– Logically unique: the data type, value range or field length is

uniquely defined system-wide inside SAP BW.– From the technical point of view, an InfoObject can viewed as a

database field.


SAP UA

Evolution from a SAP ERP Database Object to an SAP BW InfoObject

R/3

Table Costcenter

BW ExtraktorSAP ERPSAP BW InfoObjects

SAP BW DataSource


InfoObject"0COSTCENTER"

SAP Business Information Warehouse!!

COAccounting

COAccounting

HRHuman

Ressources

HRHuman

Ressources

COSTC ...

Table Costcenter

Table EmployeeEMPLO COST_CENTER ...

DataSourceCostCenter

Definition&

Mapping


SAP UA

InfoObjects Are “Bricks” for Data Structures


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SAP UA

InfoProviders “Provide” Access to Data Records

InfoProviders:• Are data storage inside SAP BW• May store data records physically (persistent)• May also be used to access data stored outside SAP BW virtually

(transparent views)• May be accessed with front end tools such as SAP


• May be accessed with front end tools such as SAP BusinessExplorer

Note: A query is a “view” to data within an InfoProvider and does not contain physical data.


SAP UA

InfoProviders

• InfoProviders with physical data: – InfoCubes

• Contain data optimized for fast multi-dimensional analysis.– DataStore Objects

• Contain detailed data.• Used for high data volumes stored in normal database tables.

Oft d “d t ” f I f C b


• Often used as “data source” for InfoCubes.

• InfoProviders with virtual data:– MultiProviders

• Often used to create “views” above two or more InfoCubes with the same Characteristics but different Key Figures.

• Data resides in the InfoCubes involved and data redundancy is avoided.– VirtualProviders

• Data stored somewhere outside SAP BW. • Some ERP systems provide data storage which may be accessed directly

by SAP BW without changing the end user ‘s view to the data.


SAP UA

InfoCubes

• Provide data storage used for reporting and online analysis.

• Consist of Key Figures and Characteristics.• Contain data stored multi-dimensionally and often aggregated

(week, month).• Use star database schema consisting of a fact table surrounded


Use star database schema, consisting of a fact table surrounded by dimension tables.

• Use a maximum of 3 + 13 dimension tables.– 3 dimension tables are pre-defined by SAP.

• Time, Unit and DataPackage (for technical information)– 13 dimensions may be used by InfoCube developers.

Note: In practice, good InfoCube design should not exceed 6-8 dimensions (+ the 3 above) so 13 dimensions are plenty.

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SAP UA

DataStore Objects

• Contain single data records such as invoices, purchase orders or customer order items.

• Consist of key fields (such as “order number”, “order position number”) and data fields (Key Figures and Characteristics such as “sales amount”, “ net value”, “customer id”, “material number”).


• Store data records in relational database tables.• Often contain massive volumes of data.


SAP UA

InfoCube versus DataStore Object

• Data Warehouse, Operational Data Store and Data Marts are general layers in a Data Warehouse Architecture.

BI1-M2-01-Data Warehouse


• Data Warehouse and Operational Data Store may be implemented with DataStoreObjects.

• Data Marts will be implemented with InfoCubes.


SAP UA




Agenda


j– InfoCubes

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SAP UA

InfoObjects

• InfoObjects– Key Figures

• Revenue, Sales Amount, Net Value, ….– Characteristics

• Customer, Region, Zip Code, …Units


– Units• Unit of Measurement, Currency, …

– Time• Calender Year, Fiscal Year, Month, Day, Quarter, ….

– Some Technical Stuff• DataPackageID, RequestID, …


SAP UA

Key Figure Definition: Revenue

Amount, Quantity, .. …

Data Type: integer,


EUR, USD, … (fix)

Pieces, inch, %, … (fix)

Unit / Currency (fix) / Currency reference

Data Type: integer, float, char(10), …


SAP UA

Key Figure Definition: Revenue (cont.)

Aggregation: Last Value,

Jan Feb Mar Apr May Jun

500520 515 520 520

Last valueNo Employee per Month

521

Last value


Aggregation: Summation, Minimum, Maximum

gg g ,Maximum, Average…

Reference Characteristic, e.g. QuarterThe reference characteristic allows the use of a function to aggregate data instead of summation.Example: Number of Employees at the end of the quarter. Sum does not make sense!

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If the Key Figure is non-cumulative (e.g., warehouse stock), this field defines an InfoObject representing non-cumulative change. This


InfoObject is either positive or negative. So, the stock amount can be calculated from it. Two fields are used to

calculate the non-cumulative amounts. Inflow is the InfoObject which represents the stock inflow amount. Outflow is vice versa.


SAP UA




SAP UA

Characteristic Definition: Sales Organisation


Data Types: Num, Char, Date, …

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Conversion Routine

Database values• Are stored in internal format

appropriate to the database– Date as YYYYMMDD

• Are presented to a user in external format according to his local settings, e.g., in


g ,– Europe

• Date: DD.MM.YYYY• Numbers: 1.234,56

– US• Date: MM/DD/YYYY• Numbers: 1,234.56

Transformation external internal format is performed by a conversion routine


SAP UA

ALPHA Conversion Routine

Alphanumeric database fields• Datatype CHAR in SAP• Can store character and number values• Have conversion exit ALPHA as default

– Eliminates leading blanks after user input• User input of ‚RB0010‘ and ‚ RB0010‘ refers to same object


p j– Stores numbers with leading 0s in database

• Numeric values are stored in natural order in database, e.g. 0002 first, then 0010

Material Group in SAP Business Content has numerical values with trailing blanksConversion exit ALPHA must not be used


SAP UA

MATN1 Conversion Routine

Database field Material often requires special treatment.• Datatype CHAR in SAP• Conversion exit MATN1 is used• Edit format can be defined in transaction OMSL

– E.g. _ _-_ _ _ _ User Input RB-0010 is stored as RB0010


Since the OMSL format setting is system-wide, we do not use it in the Bike Company Curriculum.

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SAP UA

Characteristic Definition: Sales Organisation (cont.)An InfoObject may

have attributes!


Texts:Descriptive textsMulti-language textsTime dependent texts


SAP UA

Characteristic Definition: Sales Organisation (cont.)


Attributes

Usable for OLAP operations or display only


SAP UA

Time Characteristics

• Time characteristics are always necessary and define the time-related reference point for data analysis purposes.

• Time characteristics are predefined by SAP and cannot


be changed.

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SAP UA

Units/Currencies

• Units and Currencies are used to define Key Figures in more detail.• A Unit may be an InfoObject which defines the Unit of a Key Figure.• A Currency may be an InfoObject which defines the Currency of a

Key Figure• Examples:

0CURRENCY


– 0CURRENCY – 0BASE_UOM


SAP UA




Agenda


j– InfoCubes


SAP UA

5 Steps to Define a DataStore Object

5 steps to Define an DataStore Object1) Define a name for a

DataStoreObject2) Choose the key fields3) Choose the data fields4) Define attributes used for data

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analysis5) Activate the DataStoreObject

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SAP UA

Choosing InfoObjects to Build a DataStore Object

• Select the relevant InfoObjects– Direct InfoObject name input (1) or– Choose InfoObjects by InfoObjectCatalog and drag & drop the

InfoObjects (2)



SAP UA

7 Steps to Define an InfoCube

7 Steps to Define an InfoCube1) Choose a name for an InfoCube2) Create Dimensions as needed3) Assign Characteristics to Dimensions4) Choose Time Characteristics5) Choose Key Figures


5) C oose ey gu es6) Define Navigational Attributes7) Activate InfoCube


SAP UA

Create New Dimensions If Needed


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SAP UA

What is a Dimension Inside SAP BW?

• A dimension is a group of characteristics which belong to the same business object (semantically).

• Each characteristic may contain additional attributes which are relevant for data analysis – or not!!!

Navigational attributes are InfoObjects which are used to perform data analysis.


Display attributes are InfoObjects for which data analysis does not make sense (e.g. a house number or a family name)

This has an impact to cube design!

Note: In data warehouse community, the term Dimension is used for what SAP calls Characteristic .


SAP UA

Excursion: SAP BW - Enhanced Star Schema

• Attributes are not part of a dimension!


DimensionCharacteristic as part

of a dimension

Characteristic as navigation attribute

NAV

NAV

NAV


SAP UA

Displayed in the Frontend Tool


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SAP UA

Basic Characteristic and Its Navigation Attributes

1 Dimension


2. Characteristic

1. Dimension

3. Navigation Attributes are ready to be used in analysis.


SAP UA

Steps to Create an InfoCube

• Define the InfoObjects needed.– Key Figures– Characteristices

• Define which Characteristics may be chosen to create a semantic cluster for semantic dimensions.– Examples are: Sales, Production, Material Management, Finance, etc.


Examples are: Sales, Production, Material Management, Finance, etc.• Define which attributes are appropriate to perform data analysis

– OLAP attributes define them as “navigational” attributes – Non-OLAP attributes define them as “display” attributes

• Done! Deploy the InfoCube inside SAP BW!


SAP UA

Summary

• Key Figures and Characteristics are defined as InfoObjects.• InfoObjects are the smallest “bricks” to define InfoProviders

within SAP BW.• InfoProviders are used to store data within SAP BW or allow SAP

BW to access data stored somewhere else.• The most important InfoProviders are InfoCubes


The most important InfoProviders are InfoCubesand DataStore Objects.

• The definition of an SAP BW InfoCube isno Witchery!

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51 Bi Sap Bi Modeling