SAP BI Training : Transformation rules

It has been a while since my last post, there have been a lot of questions and emails going back and forth with you all. If you would like to take part in the discussion, and you are not subscribed yet, please do so in the box on the right.

Today, I am going back to basics and continuing the SAP BI training lessons. This is the reason I started this blog but
I have found out that the SAP landscape is wide and people have more questions not neccessarily pertaining to SAP Business Intelligence. Please let me know if you would like to see more posts on SAP BI.

Transformations

The topic of the day is Transformation. Transformation is all about mapping fields from source systems to destination databases. Sometimes, the mapping is one-to-one i.e you have a field in the source table that maps directly to the destination. It is also possible that the fields are not matched up correctly.

For example, length of the fields might be different in both or the way figures are calculated might also be different. A good example is VAT. The amount of value-added tax charged differs from country to country and this needs to be transformed (recalculated).
Transformation rules are used to perform these operations.

Transformation rules

Normally, when mapping fields on the InfoSource to the fields in the InfoCubes,the mapping was always one to one. In real time, this is not always the case. Some InfoObjects are not present in the InfoSource fields but have to be calculated. These calculations are done through transformations.

There are 7 different types of tranformations.

• Direct assignment
• Constants
• Reading master data
• Routines
• Formula
• Time updates
• No transformation

I shall use an example to explain these transformations. Take a look at the table below. It shows a simplistic view of a potential InfoSource that I want to transform to fields in the InfoCube. The InfoSource has the following fields, Product, Sales quantity and Price/unit. The destination InfoObjects are Product, Sales quantity, price per unit and revenue.

Direct assignment

This will copy the value in the source field directly into the target field. For example the products, sales quantity will be transformed using direct assignment.

Constants

This transformation rule will fill the target field with a specified value. For example, the import data field can be filled with today’s date.

Routines

Routines are special code written to handle complex cases. There are start routines, end routines and expert routine Start routines are used to pre process the data before transformation, for example they can be used to eliminate empty fields before the process starts. This makes the process efficient when there a lot of records being imported and a handful will be empty fields.

End routines are used to post –process the data on a package-by-package basis. This can be used for integrity checks etc.

Routines are mostly written by ABAP consultants, you as a BI consultant will have to supply the specifications for the routine you would like to implement.

I will explain the rest (Formulas, Reading master data and time updates) in a later post. Do you have any special area of SAP business intelligence you would like more explanation on? Please leave a comment and let me know.

Tagged as: sap bi training, transformation