Enterprise architecture

Enterprise architecture (EA) is concerned with the structures and behaviors of a business, especially business roles and processes that create and use business data. It has been defined as "a well-defined practice for conducting enterprise analysis, design, planning, and implementation, using a comprehensive approach at all times, for the successful development and execution of strategy. Enterprise architecture applies architecture principles and practices to guide organizations through the business, information, process, and technology changes necessary to execute their strategies. These practices utilize the various aspects of an enterprise to identify, motivate, and achieve these changes."
Practitioners of enterprise architecture, "enterprise architects", are responsible for performing the analysis of business structure and processes and are often called upon to draw conclusions from the information collected to address the goals of enterprise architecture: effectiveness, efficiency, agility, and continuity of complex business operations.
Overview.
US Code 44, Section 3601 Definition of Enterprise Architecture:
(4)“enterprise architecture”—
(A)means—
(i)a strategic information asset base, which defines the mission;
(ii)the information necessary to perform the mission;
(iii)the technologies necessary to perform the mission; and
(iv)the transitional processes for implementing new technologies in response to changing mission needs; and
(B)includes—
(i)a baseline architecture;
(ii)a target architecture; and
(iii)a sequencing plan;
EA is not just about IT. It's about understanding the mission in sufficient detail that you can make informed purchase decisions across the enterprise, in context and in a timely manner.
“Congress, OMB and the IT community are SO distracted from the underlying plot of the Clinger-Cohen Act — it was NEVER about the technology but rather how you could transform mission and support processes through the thoughtful application of technology,” Brubaker said. “Agencies were to demonstrate how they were thoughtfully applying technology by presenting clear and compelling business cases for investing in technology then holding themselves accountable for producing measurable improvements in mission and operational performance. Sadly, OMB, GSA, agencies and CIOs just couldn’t resist the temptation to over-prescribe compliance and pushing tasks that over-focused on technology and infrastructure which completely missed the point.” Paul Brubaker
https://federalnewsnetwork.com/reporters-notebook-jason-miller/2019/02/dont-exempt-dod-from-the-clinger-cohen-act-modernize-federal-it-management-instead/
The Enterprise Architecture Body of Knowledge defines enterprise architecture as a practice, which 
IT analysis firm Gartner defines the term as a discipline where an enterprise is led through change. According to their glossary, 
Each of the definitions above underplays the historical reality that enterprise architecture emerged from methods for documenting and planning information systems architectures, and the current reality that most enterprise architecture practitioners report to a CIO or other IT department manager. In a business organization structure today, the enterprise architecture team performs an ongoing business function that helps business and IT managers to figure out the best strategies to support and enable business development and business change – in relation to the business information systems that the business depends on.
Topics.
The terms "enterprise" and "architecture".
The term "enterprise" can be defined as describing an organizational unit, organization, or collection of organizations that share a set of common goals and collaborate to provide specific products or services to customers.
In that sense, the term enterprise covers various types of organizations, regardless of their size, ownership model, operational model, or geographical distribution. It includes those organizations' complete socio-technical systems, including people, information, processes, and technologies.
The term "architecture" refers to fundamental concepts or properties of a system in its environment, embodied in its elements, relationships, and in the principles of its design and evolution.
Understood as a socio-technical system, the term enterprise defines the scope of the enterprise architecture.
Scopes.
Perspectives, or beliefs, held by enterprise architecture practitioners and scholars, with regards to the meaning of the enterprise architecture, typically gravitate towards one or a hybrid of three schools of thought:
One’s belief with regards to the meaning of enterprise architecture will impact how one sees its purpose, its scope, the means of achieving it, the skills needed to conduct it, and the locus of responsibility for conducting it
Architectural description of an enterprise.
According to the standard ISO/IEC/IEEE 42010, the product used to describe the architecture of a system is called an "architectural description". In practice, an architectural description contains a variety of lists, tables, and diagrams. These are models known as "views". In the case of Enterprise Architecture, these models describe the logical business functions or capabilities, business processes, human roles and actors, the physical organization structure, data flows and data stores, business applications and platform applications, hardware, and communications infrastructure.
The UK National Computing Centre EA best practice guidance states:
Normally an EA takes the form of a comprehensive set of cohesive models that describe the structure and functions of an enterprise. The individual models in an EA are arranged in a logical manner that provides an ever-increasing level of detail about the enterprise.
The architecture of an enterprise is described with a view to improving the manageability, effectiveness, efficiency, or agility of the business, and ensuring that money spent on information technology (IT) is justified.
Paramount to "changing" the enterprise architecture is the identification of a sponsor. His/her mission, vision, and strategy, and the governance framework define all roles, responsibilities, and relationships involved in the anticipated transformation. Changes considered by enterprise architects typically include:
A methodology for developing and using architecture to guide the transformation of a business from a baseline state to a target state, sometimes through several transition states, is usually known as an enterprise architecture framework. A framework provides a structured collection of processes, techniques, artifact descriptions, reference models, and guidance for the production and use of an enterprise-specific architecture description.
Benefits.
The benefits of enterprise architecture are achieved through its direct and indirect contributions to organizational goals. It has been found that the most notable benefits of enterprise architecture can be observed in the following areas:
Examples.
Documenting the architecture of enterprises is done within the U.S. Federal Government in the context of the Capital Planning and Investment Control (CPIC) process.
The Federal Enterprise Architecture (FEA) reference model guides federal agencies in the development of their architectures.
Companies such as Independence Blue Cross, Intel, Volkswagen AG and InterContinental Hotels Group use enterprise architecture to improve their business architectures as well as to improve business performance and productivity.
For various understandable reasons, commercial organizations rarely publish substantial enterprise architecture descriptions. However, government agencies have begun to publish architectural descriptions they have developed. Examples include:
Relationship to other disciplines.
According to the Federation of EA Professional Organizations (FEAPO), enterprise architecture interacts with a wide array of other disciplines commonly found in business settings. According to FEAPO:
As enterprise architecture has emerged in various organizations, the broad reach has resulted in this business role being included in the information technology governance processes of many organizations. While this may imply that enterprise architecture is closely tied to IT, it should be viewed in the broader context of business optimization in that it addresses business architecture, performance management, and process architecture, as well as more technical subjects.
Discussions of the intersection of enterprise architecture and various IT practices have been published by various IT analysis firms. Gartner and Forrester have stressed the important relationship of enterprise architecture with emerging holistic design practices such as Design Thinking and User Experience Design. Analyst firm Real Story Group suggested that enterprise architecture and the emerging concept of the digital workplace were "two sides to the same coin." The Cutter Consortium describes enterprise architecture as an information and knowledge-based discipline.
The enterprise architecture of an organization is too complex and extensive to document in its entirety, so knowledge management techniques provide a way to explore and analyze these hidden, tacit, or implicit areas. In return, enterprise architecture provides a way of documenting the components of an organization and their interaction, in a systemic and holistic way that complements knowledge management.
In various venues, enterprise architecture has been discussed as having a relationship with Service Oriented Architecture, a particular style of application integration. Research points to enterprise architecture promoting the use of SOA as an enterprise-wide integration pattern.
Tools.
The following table lists some notable enterprise architecture tools listed by Gartner and Forrester Research in their 2013, 2014, 2017 and 2018 reports.
Challenges.
Establishing Enterprise Architecture, as accepted, recognized, functionally integrated and fully involved concept at operational and tactical levels is identified as one of the biggest challenges facing Enterprise Architects today and one of the main reasons why many EA-Initiatives fail.
Criticism.
Despite the benefits that enterprise architecture claims to provide, for more than a decade, writers and organizations raised concerns about enterprise architecture as an effective practice. Here is a partial list of those objections:
A key concern about EA has been the difficulty in arriving at metrics of success, because of the broad-brush and often opaque nature of EA projects.