This book is organized in terms of several specifically defined Levels of Abstraction. Figure 3-1 shows the structure in graphic form.
Figure 3-1: Levels of Abstraction
The levels covered are the following:
Level 0 is first a generic, low-level pattern. This is the most abstract model that makes any sense. Among other things, it is directly the basis for the enterprise models in Level 1.
At right angles to this scheme, two categories of metadata are relevant to enterprise-oriented models. The term “metadata” refers to the data that are used to describe other data. Typically, these are such things as entity and attribute ...