In Order to do modelling we should understand concepts first . After understanding the BW concepts , we will be explaining about BW database design . In this lesson I will be detailing about some of the concepts like Info Objects & types.Types of data and behavior of data
INFO OBJECTS :
Suppose I have data like below in R/3
fig 1
This data we need to extract to BW side . Your basic modelling starts with defining Info object.
Case 1 :
Imagine we don't want price information in target , In this case we don't need fields 4 & 5 in above example .
Case 2 :
Suppose if you want to create a new field in target which calculates total revenue which is product of Revenue * Rev Unit (8 & 9) in above figure . At this time we have to create 1 extra info object for storing calculated totals .
2.TYPES OF INFO OBJECTS
Basically categorized in 4 types .
CHARACTERS
KEY FIGURES
UNIT CHARACTERS
TIME CHARACTERS
KEY FIGURES:
The objects which we analyse in the reports has to be defined as KEY FIGURES.These are measurable objects. Key figures are always Numeric. Its not that wherever you see number , we should define them as key figures . Suppose in the below table Customer Number , Though number cannot be defined as KEY FIGURE .
Fig 2
In the above example , can we compare CUST1 & CUST 2 -- No we cant
Can we compare MAT1 & MAT2 -- no we cant
Can we compare 200 & 100 in Price of material . yes we can . 200 is greater than 100 .So we define this type of fields as Key figures
Shall we measure unit AUD
QTY-- can be measured
Revenue-- can be measured.
All the objects which we can measure and analysed can be defined as KEY FIGURES.
In business Objects we will call these key figures as MEASURES.
KPI -- Key performance Indicators
What is my growth
what is my profit
CHARACTERS :
On what basis we analyse the key figure is nothing but CHARACTER.
Lets us say we are analysing revenue , is this analysis complete with this .No , On what basis you are going to analyse KEY FIGURE .
In our above Fig 1 Customer Number & Material # should be defined as Characters
UNIT CHARACTERS:
It will give value for the key figures , Without the unit there is no value.Where ever we use key figure , unit character will be always following KEY FIGURE
In the fig 1 , Unit price , Qty Unit & Rev Unit should be defined Unit Characteristics
TIME CHARACTERS
These hold data related to date of transaction, year of transaction , Month of transaction.
In the fig 1, Date of Transaction should be defined as Time Characters
Take any application , we can categorise fields into the above 4 types
Lets take an example of Banks Monthly statement
Date of Transaction -- Time Char
INR/USD------------------ Unit Char
Your Account Number --- Character
Opening Balance /Closing balance -- Key Figure
3.TYPES OF DATA
In SAP terms , data is categorized into two types ,
MASTER DATA
TRANSACTIONAL DATA
MASTER DATA :
The details level of information of character Info Object is called as Master data.This data is nothing to do with occurrence of business. Master data will not change frequently .
Always remember , primary key should be character , Not key figure
Data form MARA , LFA1
Information of Customer
Information of Vendors
Information of Material
TRANSACTIONAL DATA :
Data related to occurrence of business is called as Transactional data . This data changes frequently.
Lets take an example of bank balance , This gets updated when you deposit cash / withdraw cash .
4. BEHAVIOR OF DATA
a.) MASTER DATA:
Master data gives present truth , Data in the Master Data Overwrites .
Imagine Customer no & Address
b.) Transactional Data :
Data in the transaction table adds up . Transactional data gives the FACT truth.truth. Thats why we call transactional tables as FACT tables .
Will system allow to use KEY FIGURE in MASTER DATA ??
Answer :
Yes we can use ,
for example you are storing your salary details in Master data
Storing salary details in Transactional Tables
Storing Salary details in Master Table
new salary override old salary and you will be having the below record in Database
NON CUMULATIVE KEY FIGURES ;
These will not add up in the Transaction table
Storing material Price in Transaction table :
If we generate report , for FACT table entry it shows 250(100+150) and for Master table it shows 150
If you dont want to sum up these key figures , we should define them as Non Cumulative .
Take the first value / last value of the Month .
We should define them as Non Cumulative key figure last value with respect to year .Any Key figure you want to create in FACT table , By defaults the values sum up , If you don't want this behavior , you have to define them as Non cumulative key figures .
Why can't we maintain them in Master table rather defining as” non cumulative key figures” ?
When we develop a report we always generate on transactional tables . To maintain History
STEPS OF MODELLING
IDENTIFY THE NUMBER OF INFO OBJECTS TO BE CREATED IN BW
IDENTIFY EACH INFO OBJECT AS WHAT TYPE IT HAS TO BE CREATED.
IDENTIFY WHAT TYPE OF DATA YOU NEED TO EXTRACT
