The core subject area entities from the Enterprise Data Model form the nucleus upon which detailed Business Area Models are developed. The advantage of developing Subject Area Models directly from the Enterprise Data Model is that it insures that the keys will match and supports the integration of Subject Area data with other Subject Area data models, the Data Warehouse Model or back into the Enterprise Data Model itself. The focus of the Enterprise Data Model is enterprise-wide planning and communication of requirements throughout the organization. The focus of the Data Warehouse Model is centralized, integrated, dependable data that can be used by the organization as a whole and provide data to local data marts or decision support systems. The focus of the Business Area Models is the development of local data marts or decision support systems and the development of applications for those same functional areas.
Data models are the accepted way for planning and designing an integrated data architecture.
Each model is derived from the Enterprise Data Model for that industry. This supports the integration of data across each level of models. The Enterprise Data Model becomes the source for creating new functional business area models and extending the Data Warehouse Model. New data, identified during business area development, that is considered to be of sufficient importance can be propagated up to the Enterprise Data Model. This enhances the Enterprise Data Model and reflects new information learned about the enterprise during detailed business area analysis.