A definition for architecture is: the fundamental organization of a system, embodied in its
components, their relationships with each other and their environment, and the principles governing
its design and evolution. (ANSI/IEEE STD 1471-2000)
Enterprise architecture refers to an architecture description of the total enterprise, which describes
the meta-architecture, business architecture and the systems architecture (that implements and
supports the business architecture).
The meta-architecture describes the business and systems architectures on a meta-level and
contains the rules of design and evolution of both the business and systems architectures.
The business architecture describes the business part of the enterprise architecture. It describes
strategy, governance, structure, behaviour and functions that are key to the enterprise.
The systems architecture describes systems (IT/IS) from the applications, data structure and
technology points of view. The systems architecture exists to describe how the business
architecture is realized by the systems and technology implemented in the enterprise.
Good enterprise architecture allows impact analysis across the other dimensions as business and
systems change over time. For example: Should a business process need to be adapted because of
some external demand, the impact on the underlying systems should be immediately apparent. The
impact should be visible and traceable through the enterprise architecture models.
