While the development process that has been described is normal for almost every shop,
there is a problem. Over time, a serious amount of overlap between different applications
starts to emerge. Because of the need to define and enforce the definition of the scope of
an application rigorously, the same or similar functionality starts to appear across multiple
applications. When this happens, there start to appear redundant data. The same or
similar data element appears in multiple applications.

The Corporate Data Model

When redundant data start to appear, the very integrity of the data comes into question.
It is because of this method of developing systems and the inevitable lack of integrity of
data across applications that there is recognition of the need for corporate data, not
application data.

Fig. 14.1.5 shows the corporate data model.

Chapter 14.1: Data Models Across the End-State Architecture