Page "Data warehouse" Paragraph 62

The top-down design methodology generates highly consistent dimensional views of data across data marts since all data marts are loaded from the centralized repository.

Top-down design has also proven to be robust against business changes.

Generating new dimensional data marts against the data stored in the data warehouse is a relatively simple task.

The main disadvantage to the top-down methodology is that it represents a very large project with a very broad scope.

The up-front cost for implementing a data warehouse using the top-down methodology is significant, and the duration of time from the start of project to the point that end users experience initial benefits can be substantial.

In addition, the top-down methodology can be inflexible and unresponsive to changing departmental needs during the implementation phases.