Software Fortresses: Modeling Enterprise Architectures

2.2 Fortress“Ally Diagram

A single fortress by itself is not very interesting. It is the relationship between fortresses that defines the enterprise architecture. A fortress“ally diagram ( FAD ) shows all of the enterprise fortresses and the ally relationships between them. Figure 2.2 shows an example of a FAD for a bill payment system.

The important features of a FAD are as follows :

• Each fortress should be identified with a name and a type in the format name ::type so that the appropriate fortress overview can be consulted for more detail.

• Each drawbridge should be identified (with either labeled arrows or boxes) so that the appropriate drawbridge overview can be consulted for more detail.

• Each treaty should be identified so that the appropriate treaty overview can be consulted for more detail.