When designing the architecture of a data warehouse system we have to raise different environments for which data must pass en route to its Data mart or target cube. Given the amount of changes that have to do, and normally the DWH, besides fulfilling its function of support analytical
requirements, performs a data integration function that will form the Corporate store and they will have to be also consulted the traditional way by the operational systems, it is recommended to create different data areas in the path between source systems and OLAP tools.

Each of these areas as characterized by the functions performed, how data is organized in the same, and what type of need can service. The area that is 'at the end of the road' is important, but it will not be the only store data that will exploit the reporting tools...