The Data model is somehow the result of the previous steps and summarizes the structure (entities) relationships between all the Data Sources. It’s an important description as it will support the Data expert to build the extraction needed to get the right data. For that it’s really important for this Logical Data Model to be validated by the business beforehand.

The Data Model we are interested in is the  logical one (at the opposite to the physical Data Model) in a way it can not reflect exactly the way the data are really stored in the data sources. The purpose here is not to describe the real structure of the data but more to provide some guidance on how to be able to query them efficiently.