1.1. Definition of Enterprise Architecture
The US government defines Enterprise Architecture (EA) as “ an active, strategic data base which defines a business, what is necessary to operate a business, including the technologies that are needed to support its operations, and the transition processes necessary for implementing new technologies in response to changes in the needs of the business” (Hite, 2002).
Several recent proposals have been put forward for tools that can help to apply the descriptive practices of EA(s). Among these tools are frameworks, methods and modelling languages. These tools have characteristics which differentiate one from the other.
Zachman (1987) define an Enterprise Architecture framework as: “a taxonomy for organising architectural artefacts, such as: documents, specifications and project models, which take into account who the artefact is for (for example, a business owner or builder) and what the specific problem is (for example, data and functionality)”. With regard to the current frameworks of EA, (Zachman, 1987; Sowa & Zachman, 1992; CIO, 1999; CIO, 2001; The Open Group, 2006; Schekkerman, 2006; OMB, 2009) describe a consistent vision and approach, as well as sharing a common concern about the various components of a business that must be considered and analysed. An EA framework supports a way of globally integrating Business, Information, IT Systems, Technology and Technological Infrastructures, aligning the support to the business strategy, principles, goals and objectives, and bearing in mind points of view on governance, security and privacy.
A complete set of EA models, objects and artefacts would include the following components:
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EA/Strategic Direction: This creates a vision for the business which will guide and control the development of each area of the architecture and their components;
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Business Architecture: This describes the present, and the target, business environments, focusing on the business’s activities and operations;
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Information Architecture: This details the present, and the target, business environments, focusing on the business process, the information flows and the business’s interactions;
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Information System Architecture: This defines the types of application systems that are relevant to the business, and also describes the applications as logical groups of resources that make up the management of information and support for the business processes defined in the Business and Information Architecture´s;
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Technological Architecture: This describes the logical software and hardware capabilities that are required to support the deployment of business, data, and application services. This includes IT infrastructure, middleware, networks, communications, processing, standards, etc.
Figure 1 shows brief details of the evolution of EA frameworks.
Figure 1. Evolution of EA frameworks