NIST Enterprise Architecture Model: Difference between revisions

Revision as of 23:32, 16 July 2013

Revision as of 00:31, 17 July 2013

Line 5:

== Overview ==

The NIST Enterprise Architecture Model is a five-layered model for [[enterprise architecture]], designed for organizing, planning, and building an integrated set of information and information technology architectures. The five layers are defined separately but are interrelated and interwoven.<ref name="CIOC99"/> ThisThe interrelationmodel betweendefined the architectureinterrelation layersas is defined in the modelfollows:<ref name="FG89"/>

* ''Business Architecture'', which drives the information architecture

* ''Information architecture'', which prescribes the information systems architecture

* ''Information systems architecture'', which identifies the data architecture

* ''Data Architecture'', which suggests specific data delivery systems, and

* ''Data Delivery Systems'', (Software, Hardware, Communications) support the data architecture.

The hierarchy in the model is based on the notion that an organization operates a number of business functions, each function requires information from a number of source, and each of these sources may operation one or more operation systems, which in turn contain data organized and stored in any number of data systems.<ref>John O'Looney (2002). ''Wiring Governments: Challenges and Possibilities for Public Managers''. Greenwood Publishing Group. p.67.</ref>

Line 38:

In the third working group on systems planning was chaired by [[John Zachman]], and adopted the [[Zachman Framework]] as a basis for discussion.

The fifth working group on architectures and standards was chaired W. Bradford Rigdon of the McDonnell Douglas Information Systems Company (MDISC), a division of [[McDonnell Douglas]]. ThisRigdon et al. (1989) <ref name="WBR 1989" >W. Bradford Rigdon (1989) "Architectures and Standards". In: ''Information Management Directions: The Integration Challenge''. E.N. Fong and A.H. Goldfine (eds.). NIST Sept 1989. p. 135-150</ref> explained that discussions about architecture in that time mostly focus on technology concerns. Their aim was to "takes a broader view, and describes the need for an ''enterprise architecture'' that includes an emphasis on business and information requirements. These higher level issues impact data and technology architectures and decisions."<ref>Rigdon (1989), p. 136</ref> In order to do so, the working group addressed three issues<ref>Fong and Goldfine (1989, p. 136)</ref>:

* The levels of architecture in an enterprise

* Problems addressed by architecture

Line 49:

== NIST Enterprise Architecture Model topics ==

=== Foundations ===

[[File:SampleNIST ElementsAE of an Enterprise Architecturemodel (1989).jpg|thumb|Sample ElementsModel of an Enterprise Architecture, (1989).]]

According to Rigdon et al. (1989) an architecture is "a clear representation of a conceptual framework of components and their relationship at a point in time"<ref> Rigdon et al. (1989, p. 136)</ref>. It may for example represent "a view of a current situation with islands of automation, redundant processes and data inconsistencies"<ref name= "Rig 1989, 137"> Rigdon (1989), p. 137 </ref>or a "future integrated automation information structure towards which the enterprise will move in a prescribed number on years."<ref> Rigdon et al. (1989, p. 137-38)</ref> The role of standards in architecture is to "enable or constrain the architecture and serve as its foundation".<ref name="Rig 1989, 137"/>

In 1989 presentation of the NIST Enterprise Architecture Model Rigdon et al. (1989) <ref name="WBR 1989" >W. Bradford Rigdon (1989) "Architectures and Standards". In: ''Information Management Directions: The Integration Challenge''. E.N. Fong and A.H. Goldfine (eds.). NIST Sept 1989. p. 135-150</ref> explained that discussions about architecture in that time mostly focus on technology concerns. Their aim was to "takes a broader view, and describes the need for an ''enterprise architecture'' that includes an emphasis on business and information requirements. These higher level issues impact data and technology architectures and decisions."<ref>Rigdon (1989), p. 136</ref>

In order to develop an enterprise architecture Rigdon et al.acknowledge<ref>Rigdon (1989), p. 137) acknowledge, that136</ref>:

* There are multiple ways to develop an architecture

* There are multiple ways to implement standards

* Development and implementation should be customized to the environment

* Yet, every architecture itself can be divided into different levels.

The different levels of an enterprise architecture can be visualized as a pyramid with "the business unit at the top and the delivery system at the base. An enterprise is composed of one or more Business Units that are responsible for a specific business area. The five levels of architecture are Business Unit, Information, Information System, Data and Delivery System."<ref name="Rig 1989"> Rigdon (1989), p. 137<"/ref>

The separate levels of an enterprise architecture are interrelated in a special way. TheOn "depictionevery atlevel onethe levelarchitectures assumes or dictates thatthe architectures at the higher level.".<ref name="Rig 1989"/> The illustration on the right gives an example of which elements can constitute an Enterprise Architecture.

=== Levels of architecture ===

The separate levels of an enterprise architecture are interrelated in a special way. The "depiction at one level assumes or dictates that architectures at the higher level.".<ref name="Rig 1989"/> The illustration on the right gives an example of which elements can constitute an Enterprise Architecture.

[[File:Sample Elements of an Enterprise Architecture (1989).jpg|thumb|Sample elements of an Enterprise Architecture (1989).]]

Each layer of architecture in the model has a specific intention:<ref> Rigdon et al. (1989, p. 139-140)</ref>

* Business Architecture level: This level can picture the total or a subunit of any corporation, which are in contact with external organizations.

* Information architecture level: This level specifies types of content, presentation forms, and format of the information required.

* Information systems architecture level: Specifications for automated and procedure-oriented information systems.

* Data Architecture level: Framework for maintenance, access and use of data, with data dictionary and other naming conventions.

* Data Delivery Systems level: Technical implementation level of software, hardware, and communications that support the data architecture.

A sample elements of how the [[Enterprise Architecture]] can be described in more detail is shown in the illustration.

== Applications ==