An enterprise architecture framework (EA framework) defines how to create and use an enterprise architecture. An architecture framework provides principles and practices for creating and using the architecture description of a system. It structures architects' thinking by dividing the architecture description into domains, layers, or views, and offers models – typically matrices and diagrams – for documenting each view. This allows for making systemic design decisions on all the components of the system and making long-term decisions around new design requirements, sustainability, and support.
Overview
Enterprise architecture regards the enterprise as a large and complex system or system of systems. To manage the scale and complexity of this system, an architectural framework provides tools and approaches that help architects abstract from the level of detail at which builders work, to bring enterprise design tasks into focus and produce valuable architecture description documentation.
The components of an architecture framework provide structured guidance that is divided into three main areas: Descriptions of architecture: how to document the enterprise as a system, from several viewpoints. Each view describes one slice of the architecture; it includes those entities and relationships that address particular concerns of interest to particular stakeholders; it may take the form of a list, a table, a diagram, or a higher level of composite of such. Methods for designing architecture: processes that architects follow. Usually, an overarching enterprise architecture process, composed of phases, broken into lower-level processes composed of finer grained activities. A process is defined by its objectives, inputs, phases (steps or activities) and outputs. It may be supported by approaches, techniques, tools, principles, rules, and practices. Organization of architects: guidance on the team structure and the governance of the team, including the skills, experience, and training needed.
History
The earliest rudiments of the step-wise planning methodology currently advocated by The Open Group Architecture Framework (TOGAF) and other EA frameworks can be traced back to the article of Marshall K. Evans and Lou R. Hague titled "Master Plan for Information Systems" published in 1962 in Harvard Business Review.
Since the 1970s people working in IS/IT have looked for ways to engage business people – to enable business roles and processes - and to influence investment in business information systems and technologies – with a view to the wide and long term benefits of the enterprise. Many of the aims, principles, concepts and methods now employed in EA frameworks were established in the 1980s, and can be found in IS and IT architecture frameworks published in that decade and the next.
By 1980, IBM's Business Systems Planning (BSP) was promoted as a method for analyzing and designing an organization's information architecture, with the following goals: understand the issues and opportunities with the current applications and technical architecture; develop a future state and migration path for the technology that supports the enterprise; provide business executives with a direction and decision making framework for IT capital expenditures; provide the information system (IS) with a blueprint for development.
In 1982, when working for IBM and with BSP, John Zachman outlined his framework for enterprise-level "Information Systems Architecture". Then and in later papers, Zachman used the word enterprise as a synonym for business. "Although many popular information systems planning methodologies, design approaches, and various tools and techniques do not preclude or are not inconsistent with enterprise-level analysis, few of them explicitly address or attempt to define enterprise architectures." However, in this article the term "Enterprise Architecture" was mentioned only once without any specific definition and all subsequent works of Zachman used the term "Information Systems Architecture".
In 1986, the PRISM architecture framework was developed as a result of the research project sponsored by a group of companies, including IBM, which was seemingly the first published EA framework.
In 1987, John Zachman, who was a marketing specialist at IBM, published the paper, A Framework for Information Systems Architecture. The paper provided a classification scheme for artifacts that describe (at several levels of abstraction) the what, how, where, who, when and why of information systems. Given IBM already employed BSP, Zachman had no need to provide planning process. The paper did not mention enterprise architecture.