This write-up, which is the first one in the series, intends to provide a brief overview on Enterprise Architecture and then further goes on to illustrate the need for an Enterprise Architecture Framework.
ISO/IEC 42010: 2007 defines "architecture" as:
"The fundamental organization of a system, embodied in its components, their relationships to each other and the environment, and the principles governing its design and evolution."
TOGAF embraces but does not strictly adhere to ISO/IEC 42010: 2007 terminology. In TOGAF, "architecture" has two meanings depending upon the context:
- A formal description of a system, or a detailed plan of the system at component level to guide its implementation
- The structure of components, their inter-relationships, and the principles and guidelines governing their design and evolution over time
The Definition of Enterprise
The term "enterprise" refers to any collection of organizations that has a common set of goals. For example, an enterprise could be a government agency, a whole corporation, a division of a corporation, a single department, or a chain of geographically distant organizations linked together by common ownership.
It is important to here note that the term "enterprise" in the context of "enterprise architecture" can be used to denote both  an entire enterprise as a collection encompassing all of its information and technology services, processes, and infrastructure — and  a specific domain within the enterprise. Nevertheless in both cases, the architecture crosses multiple systems and multiple functional groups within the enterprise.
Defining Enterprise Architecture
Enterprise architecture is a structural approach that optimizes the often fragmented organization wide processes (both manual and automated) into an integrated environment that is responsive to change and enables delivering the enterprise's business strategy.
Domains of Enterprise Architecture
There are four architecture domains that are commonly accepted as subsets of an overall enterprise architecture, all of which TOGAF is designed to support.
- Business Architecture
The Business Architecture defines the business strategy, governance, organization, and key business processes.
- Data Architecture
The Data Architecture describes the structure of an organization’s logical and physical data assets and data management resources.
- Application/Solution Architecture
The Application or Solution Architecture provides a blueprint for the individual application systems to be deployed, their interactions, and their relationships to the core business processes of the organization.
- Technology/Deployment Architecture
The Technology or Deployment Architecture 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.
The Open Group Architecture Framework (TOGAF) provides the core methods and tools for assisting in the acceptance, production, use, and maintenance of an enterprise architecture. It is based on an iterative process model supported by best practices and a re-usable set of existing architecture assets.
Illustrating the need for TOGAF
Architecture design is a technically complex process, and the design of heterogeneous, multi-vendor architectures is particularly complex. TOGAF plays an important role in helping to de-mystify and de-risk the architecture development process. TOGAF provides a platform for adding value, and enables users to build genuinely open systems-based solutions to address their business issues and needs.