The
The Enterprise Architecture is the explicit description of
the current and desired relationships among business and management process and
information technology. It describes the "target" situation, which
the agency wishes to create and maintain by managing its IT portfolio.
The documentation of the Enterprise Architecture should
include a discussion of principles and goals.1
For example, the agency's overall management environment, including the balance
between centralization and decentralization and the pace of change within the
agency, should be clearly understood when developing the Enterprise
Architecture. Within that environment, principles and goals set direction on
such issues as the promotion of interoperability, open systems, public access,
end-user satisfaction, and security.
This guidance adapts a five component model used in the
National Institute of Standards and Technology (NIST) Special Publication
500-167, "Information Management Directions: The Integration
Challenge." Agencies are permitted to identify different components as
appropriate and to specify the organizational level at which specific aspects
of the components will be implemented. Although the substance of these
components, sometimes called "architectures" or
"sub-architectures,"2
must be addressed in every agency's complete Enterprise Architecture, agencies
have great flexibility in describing, combining, and renaming the components,
which consist of:
With the exception of the Business Processes component, the interrelationships among and priorities of these components are not prescribed by this guidance; there is no hierarchy of relationships implied. Furthermore, agencies should document not only their current environment for each of these components, but also the target environment that is desired.
Business Processes
This component of the Enterprise Architecture describes the
core business processes which support the organization's missions. The Business
Processes component is a high-level analysis of the work the agency performs to
support the organizations's mission, vision, and goals, and is the foundation
of the ITA. Analysis of the business processes determine the information needed
and processed by the agency. This aspect of the ITA must be developed by senior
program managers in conjunction with IT managers. Without a thorough
understanding of its business processes and their relation to the agency
missions, the agency will not be able to use its ITA effectively.
Business processes can be described by decomposing the processes into derivative business activities. There are a number of methodologies and related tools available to help agencies decompose processes. Irrespective of the tool used, the model should remain at a high enough level to allow a broad agency focus, yet sufficiently detailed to be useful in decision-making as the agency identifies its information needs. Agencies should avoid excessive emphasis on modeling business processes, which can result in a waste of agency resources.3
Information Flows and Relationships
This component analyzes the information utilized by the
organization in its business processes, identifying the information used and
the movement of the information within the agency. The relationships among the
various flows of information are described in this component. These information
flows indicate where the information is needed and how the information is shared
to support mission functions.4
Applications
The Applications component identifies, defines, and
organizes the activities that capture, manipulate, and manage the business
information to support mission operations. It also describes the logical
dependencies and relationships among business activities.5
Data Descriptions and Relationships
This component of the Enterprise Architecture identifies
how data is maintained, accessed, and used. At a high level, agencies define
the data and and describe the relationships among data elements used in the
agency's information systems. The Data Descriptions and Relationships component
can include data models that describe the data underlying the business and
information needs of the agency. Clearly representing the data and data
relationships is important for identifying data that can be shared corporately,
for minimizing redundancy, and for supporting new applications.6
Technology Infrastructure
The Technology Infrastructure component describes and identifies the physical layer including, the functional characteristics, capabilities, and interconnections of the hardware, software, and communications, including networks, protocols, and nodes. It is the "wiring diagram" of the physical IT infrastructure.7
Source www.whitehouse.gov/omb/memoranda/m97-16.html