Architectures are the key organizing mechanism for architectural content; they are the design or solution statement to a proposed problem or opportunity, or the documentation of an existing system. The architectures can be defined at a number of different levels, including:
- Strategic - Long term in the range of 3 - 5 years
- Tactical - Mid term in the range of 1 - 2 years
- Solution - Short term in the range of 3 - 12 Months
They also span a number of disciplines that are all incorporated into a single cohesive view of the system design. It is not possible for a single person or a single discipline to understand and to articulate the Architecture at all levels. So a Business Architect is required to interpret the Strategic Plan, an Information Architect would categorize the enterprise's data, an Application Architect would articulate the interfaces between Components, and a Technology Architect is required to define the Servers and Devices that ultimately do the work. Their work results in four core domain architectures:
- Business Architecture
- Information Architecture
- Application Architecture
- Technology Architecture
Most frameworks describe analogous or similar subsets of an Enterprise Architecture, as the division is based largely on organizational units performing work in these areas.
Baseline, Transition and Target Architectures can also be defined.