http://www.dodccrp.org/events/5th_ICCRTS/papers/Track7/067.pdfThe C4ISR Architecture Framework: History, Status, and Plans for Evolution
P. Kathie Sowell
1
The MITRE Corporation
McLean, Virginia
Abstract
An architecture is “the structure of components, their relationships, and the principles
and guidelines governing their design and evolution over time.”
-- C4ISR Architecture Framework Version 2.0
The Command, Control, Communications, Intelligence, Surveillance, and
Reconnaissance (C4ISR) Architecture Framework, Version 2.0, developed by the U.S.
Department of Defense (DoD) C4ISR Architecture Working Group, provides guidance
for describing architectures. It is intended to ensure that architectures developed by the
Commands, Services, and defense Agencies are interrelatable between and among the
organizations’ operational, systems, and technical architecture views, and are comparable
and integratable across Joint and multi-national organizational boundaries. The
Framework is intended to ensure that a clear audit trail exists from mission operations
and effectiveness measures to the characteristics of current and postulated C4ISR systems
and their contributions (performance and interoperability metrics) to mission operations.
This paper describes the four main components of the Framework, i.e., Architecture
Views (Operational, Systems, and Technical) and Linkages, Common Product Templates
and Common Data, Universal Guidance, and Common Building Block References.
Relationships to other popular and emerging architecture frameworks are described,
along with current plans for further evolution of the Framework.
1.0 History of the Framework
The initial impetus for the Framework came from the Defense Science Board, who
determined in the early 1990s that one of the key means for ensuring interoperable and
cost effective military systems is to establish comprehensive architectural guidance for all
of DoD. Consequently, the C4ISR Integration Task Force developed version 1.0 of the
C4ISR Architecture Framework in June of 1996, and the C4ISR Architecture Working
Group completed version 2.0 in December of 1997, under the auspices of the
Architecture Coordination Council (ACC) [C4ISR Architecture working Group, 1997].
1 The author wishes to acknowledge the support of the agencies that sponsor the work related to this paper:
the Office of the Assistant Secretary of Defense (C3I), Architectures and Interoperability Directorate; the
Federal CIO Council; and the Department of the Treasury.Page 2
In a 23 February 1998 memorandum, the Under Secretary of Defense (Acquisition &
Technology), the Acting Assistant Secretary of Defense (C3I), and the Joint Staff
Director of C4 Systems (J6) mandated the C4ISR Architecture Framework, Version 2.0
for use in all C4ISR or related architectures. In addition, they directed that the
Framework be examined as the basis for a single architecture framework for all
functional areas or domains within the DoD [Architecture Coordination Council, 1998].
2.0 Framework Overview
2.1 Why Do We Need an Architecture Framework?
Development of C4ISR architectures is a distributed process. Because there has been no
uniform guidance governing architecture development, DoD components have described
their respective architectures using a variety of disparate perspectives, formats and
terminology. It has been virtually impossible to interrelate or compare one architecture
with another, an integration process we must perform in order to identify interoperability
issues and to find opportunities for technology leveraging and sharing.
Using the Framework over time, architectures can be dovetailed and opportunities for
enhanced interoperability, integration, and cost-effectiveness will be easier to identify
and act upon.
The Information Technology Management Reform Act and the Government Performance
and Results Act require Federal Government organizations to measure the performance
of existing and planned information systems and to report performance measures
annually. The Framework can help DoD organizations to satisfy these reporting
requirements by providing uniform methods for describing information systems and their
performance in context with mission and functional effectiveness.
2.2 Framework Components
The Framework has four main parts: definitions of three standard views of any given
architecture; common products (descriptive models) and data; common building block
references; and high-level guidance in how to use the Framework to describe an
architecture.
2.2.1 Definitions of Architecture Views
The Framework defines three views of any given architecture. Figure 1 illustrates these
three views and their relationships.
Figure 1. One Architecture…Three Views
The operational view describes the tasks and activities, the operational nodes, and the
information flows between nodes that are required to accomplish or support an operation.
The operational view describes the nature of information exchanges in detail sufficient to
determine what specific degree of information-exchange interoperability is required.
The systems view translates the required degree of interoperability into a set of system
capabilities needed, identifies current systems that are used in support of the operational
requirements (or postulated systems that could be used), and facilitates the comparison of
current/postulated system implementations with the needed capabilities.
The technical view articulates the criteria that govern the implementation of required
system capabilities.
To be consistent and integrated, an architecture description must provide explicit linkages
among its various views. The Framework product set, described briefly in the next
paragraphs, provides a number of such linkages among the views.
2.2.2 Common Products and Data
Products are the representation formats, and the required data, that all of the DoD
components will use to describe their C4ISR architectures. The essential products are
those that every architecture description must include, provided that the subject view is
included in the architecture. The supporting products are those that will be needed for
some architecture descriptions, depending on the purpose of the architecture. The
Framework describes seven essential products and 19 supporting products.
It is critical to understand that a given product type is designated as “essential”
because it is one that higher-level integrators and decision makers will need to see inPage 4
order to make comparisons and budget decisions across multiple architectures.
Other products may be equally necessary, or even more necessary, for a specific
architecture effort, but if those products do not need to be seen by the higher level
decision-makers, those products are designated “supporting.” Simply stated,
“essential” means “essential for cross-architecture analysis.”
The product set was designed with relationships and connections among the products in
mind. These connections and relationships not only facilitate a more complete
representation of a given architecture, they also provide a means for relating technology
to mission requirements.
There are three essential products in the operational view:
The High-level Operational Concept Graphic (figure 2) is the most general of the
architecture-description products. Its main utility is as a facilitator of human
communication, and it is intended for presentation to high-level decision makers. This
kind of diagram can also be used as a means of orienting and focusing detailed
discussions. The graphic should be accompanied by explanatory text.
Figure 2. High-Level Operational Concept Graphic
The Operational Node Connectivity Description (figure 3) depicts the operational
nodes, the needlines between them, and the characteristics of the information exchanged.
A needline is simply an indication that two nodes need to exchange information; it does
not state how that exchange is accomplished, i.e., with what systems or networks.
Figure 3. Operational Node Connectivity Description
The Operational Information Exchange Matrix (figure 4) displays the Information
Exchange Requirements (IER) among the operational nodes, identifying who exchanges
what information with whom, why the information is needed, and what degree of
information exchange sophistication is required. The matrix describes relevant attributes
of the exchange and keys the exchange to the producing and using activities and nodes
and to the needline the exchange satisfies.
Figure 4. Operational Information Exchange Matrix
There is just one essential product in the systems view, the System Interface
Description (figure 5). However, to accommodate the range of detail that may be
required by individual architectures, this product can be shown in three perspectives:
internodal (with two levels of detail), intranodal, and intrasystem (system component).
The System Interface Description links together the operational and systems architecture
views by depicting the assignments of systems and their interfaces to the nodes and
needlines described in the Operational Node Connectivity Description.
The System Interface Description identifies the interfaces between nodes, between
systems, and between the components of a system, depending on the needs of a particular
architecture.
There is also just one essential product in the technical view, the Technical Architecture
Profile (figure 6). The Technical Architecture Profile references the technical standards
that apply to the architecture and how they need to be, or have been, implemented.Page 7
. . .
Service Area
Service
Standard
Operating System
Software
Engineering Services
User
Interface
Data Management
Data Interchange
Graphics
Client Server
Operations
Object Definition and
Management
Data Management
Window Management
Dialogue Support
Kernel
Shell and Utilities
Programming Languages
Data Interchange
Electronic Data Interchange
Graphics
FIPS Pub 151-1 (POSIX.1)
IEEE P1003.2
FIPS Pub 119 (Ada)
FIPS Pub 158 (X-Window
System)
DoD Human Computer Interface
Style Guide
FIPS Pub 158 (X-Window
System)
Project Standard
FIPS Pub 127-2 (SQL)
FIPS Pub 152 (SGML)
FIPS Pub 161 (EDI)
FIPS Pub 153 (PHIGS)
Figure 6. Example Technical Architecture Profile
In addition to the view-specific essential products described here, there are two more
essential products that apply to all three views. These are the Overview and Summary
and the Integrated Dictionary.
For each product, appendix A of the Framework contains a table presenting details of the
product attributes or characteristics. Each product attribute represents a piece of
information about a given architecture that should be captured in the product and stored
in the Integrated Dictionary.
As the Framework is used and lessons-learned are compiled, the set of information
elements needed to describe architectures will be refined.
Architecture Product Linkages – the Audit Trail That Relates Technology to
Mission Operations
The three architecture views provide a basis for analyzing proposed investments in terms
of their contributions to mission effectiveness. Because the Framework products are
closely interrelated, this kind of trace-back can be readily accomplished.
In figure 7, each of the three architecture views (operational, systems, and technical) is
represented by examples of the appropriate performance measures for that view, the
information that must be captured to evaluate whether those measures can be or are being
met, and the main Framework product or products used to capture that information.
Figure 7. Audit Trail Linking Technology to Mission Operations
As the architecture description moves from the operational view to the systems view,
information about the systems that satisfy the operational needs is overlaid on the
operational information, and the mission effectiveness measures are translated into
system performance measures. The prevailing technical architecture standards provide
implementation criteria for the systems that satisfy the operational requirements.
The sequence of products, indicated by the circled letters above, provides a mechanism
for relating the systems solutions (investments) back to their operational requirements
(mission effectiveness). The Framework does not explicitly dictate the sequence in
which products should be built, but by taking advantage of the inherent relationships
among the products, one can tailor an appropriate sequence to suit the analysis at hand.
2.2.3 Common Building Block References
There are many efforts ongoing and evolving in DoD that focus on the common goals of
interoperability, integration, and cost-effective investments. A number of reference
models and information standards exist that serve as sources for guidelines and attributes
that must be consulted while building architecture products. Each of these resources is
defined and described in its own document. Table 1 lists some of these resource building
blocks.
Figure 8. Framework Process Guidance
3.0 Adaptations Beyond DoD and Relationships to Other Frameworks
Although it was developed for C4ISR, the Framework has been used successfully in other
DoD domains, such as electronic commerce, logistics, and health services, as well as in
the Intelligence Community. Other Agencies and Departments of the Federal
Government are also adopting the descriptive product types developed for the DoD
Framework. Governments outside the United States have expressed interest in the DoD
Framework, most notably Australia, Sweden, and Israel.
A far-reaching goal of architecture development is to have a common means for
expressing architectures so that architectures can be understood and compared at many
levels -- for example, within Agencies and Departments (e.g., Service-to-Service within
DoD, or bureau-to-bureau within the Treasury Department) and across Agencies or
Departments (e.g., between DoD and the Treasury Department). Some can even envision
a world in which industry architectures can be readily compared with those of the Federal
Government (e.g., to compare the way DoD performs payroll operations with the way
IBM performs payroll operations). To this end, a number of organizations are developing
architecture frameworks that tell their architects how to describe their architectures using
common techniques and templates.
In addition to Government, industry is beginning to show interest in the C4ISR
Architecture Framework as well. The Open Group is a multi-national organization, one
of whose purposes is to develop an industry-wide common practice for architecturePage 11
description. The group has expressed a desire to incorporate some of the principles and
techniques of the C4ISR Architecture Framework into their document, which is entitled
The Open Group Architecture Framework (TOGAF) [Author’s Correspondence, 2000].
The C4ISR Architecture Framework does not dictate a specific methodology to be used
when describing architectures. An organization can devise its own method for
developing the products (that is, which supporting products should be built, in what
order, and to what level of detail), or it can use the Framework in conjunction with
another, existing methodology or framework. This flexibility has made it easier to adapt
DoD’s Framework to other domains. The sections below describe the relationships
between DoD’s Framework and some other frameworks, and how other communities are
using the architecture products prescribed in DoD’s Framework.
3.1 Relationship to the Zachman Framework
The Zachman Framework is a way of thinking about an enterprise in an organized way so
that it can be described and analyzed. The columns represent various aspects of the
enterprise that can be addressed, and the rows represent various viewpoints from which
those aspects can be described [Zachman, 1987]. Thus, each cell, formed by the
intersection of a column and a row, represents an aspect of the enterprise modeled from a
particular point of view. The architect selects and models the cells that are appropriate to
the purpose of the analysis.
As shown by the color coding in figure 9, the views and individual products of the C4ISR
Architecture Framework, Version 2.0 map to the cells of the Zachman Framework
[Sowell, 1999]. (The figure maps only the most frequently-used DoD products, not all of
them.)
Blue cells indicate that the C4ISR Architecture Framework contains operational view
products that map to the cells; orange cells indicate that the C4ISR Framework contains
systems products that map to the cells; and blue/orange cells indicate that the C4ISR
Framework contains both operational and systems products that map to the cells. (Note
that there are no red cells; this reflects the fact that no technical view products map to the
Zachman Framework. This is because the Zachman Framework does not call for the
explicit modeling of the applicable rules and standards themselves, but assumes standards
to apply within multiple cells.)
Ovals have been overlaid onto the color-coded cells. These ovals represent individual
products from the C4ISR Architecture Framework that correspond to the Zachman cell or
cells onto which the oval is overlaid. Operational products are represented by blue ovals,
and systems products by yellow or orange ovals.
Figure 9: Selected DoD Framework Products Mapped to Zachman Framework Cells
Note that in some instances a cell is blue and orange, indicating that the C4ISR
Architecture Framework contains both operational and systems products that correspond
to the cell, but only a blue oval is shown in the cell. This is because not all the C4ISR
Architecture Framework products are represented, only some of those that have been
most frequently used in DoD architectures to date. The Function/Designer cell is blue
and orange because the Operational Activity to Systems Function Matrix, while shown in
the C4ISR Architecture Framework as a systems view product, is actually a pivot point
between the operational and systems views.
Through this product-to-cell mapping, the C4ISR Architecture Framework can provide
templates and guidelines for modeling the enterprise features that correspond to the
Zachman cells.
3.2 Using the DoD Framework Product Types with the Federal Enterprise
Architecture Framework
The Federal CIO Council has developed the Federal Enterprise Architecture Framework
(FEAF) Version 1.1, which provides guidance in how to describe architectures for multi-
organizational functional segments of the Federal Government [Federal CIO Council,
1999]. As shown in figure 10, the FEAF partitions a given architecture into a Business
architecture and a Design architecture, with the Design architecture further partitioned
into Data, Applications, and Technology aspects.
Figure 10: Structure of the Federal Enterprise Architecture Framework Components
The FEAF guidance is built on the foundation of a modified Zachman Framework, with
the Spewak Enterprise Architecture Planning overlaid onto the first two rows. The first
two rows are considered essential for all architectures built in accordance with the FEAF.
Very high-level text descriptions are provided of the models that should be built to fulfill
the cells of the modified-Zachman matrix.
3.2.1 Comparison of the Federal Framework and the DoD Framework
Figure 11 illustrates the following correspondence between the FEAF components and
the DoD Framework Views: the Business architecture roughly corresponds to the DoD’s
Operational View, the Design architecture roughly corresponds to the DoD’s Systems
View, and the FEAF’s Standards roughly correspond to DoD’s Technical View. (Data is
distributed across the Operational and Systems Views in the DoD Framework.)
Figure 11: DoD Framework Views Mapped to the Federal Framework ComponentsPage 14
As stated above, the FEAF guidance is built on the foundation of the Zachman
Framework, with the Spewak Enterprise Architecture Planning overlaid onto the first two
rows. Because, as shown earlier, the DoD Framework products can be used to fill out the
cells of the Zachman Framework, the DoD products can also be used to fill out the cells
of the FEAF. Figure 12 illustrates the mapping of selected DoD Framework products to
the corresponding cells of the FEAF. Note that the FEAF has made some modifications
and annotations to the Zachman Framework rows and column names.
Figure 12: Selected DoD Product Types Mapped to the Federal Framework’s Zachman-Based Cells
3.2.2 Using the DoD Products in the FEAF: Federal Framework Pilot Architectures
The Federal CIO Council seeks to develop, maintain, and facilitate the implementation of
the top-level enterprise architecture for the Federal enterprise. This architecture will
serve as a reference point to facilitate the efficient and effective coordination of common
business processes, information flows, systems, and investments among Federal agencies.
The approach taken to develop this Federal enterprise architecture is to develop
architectures for selected high-priority cross-agency business lines, or “Federal
Segments,” which will collectively constitute the enterprise architecture.
With technical leadership provided by MITRE, a pilot effort is being conducted in which
architecture descriptions will be constructed for one of the Federal Segments, to test the
utility of the FEAF guidance. The candidate functional segment as of this writing is
Grants.Page 15
There was concern within the Federal Agencies Information Architectures Working
Group (FAIAWG) that the Zachman Framework did not provide enough detailed
direction to enable a useful architecture analysis. At this point, the FAIWG turned to the
C4ISR Architecture Framework products for this additional architecture information.
Representatives of the FAIAWG worked with MITRE to examine the DoD products;
they determined that the products were usable for the Federal Pilot with almost no
modifications. Accordingly, four of the C4ISR Architecture Framework’s essential
products and one supporting product will be used to populate the appropriate cells of the
modified Zachman Framework.
The pilot effort will produce, in accordance with the Federal Enterprise Architecture
Framework (as amended by the DoD C4ISR Architecture Framework products), a
narrow-scope architecture pilot segment that can be used to gather lessons-learned for
further development or improvement of the Federal Enterprise Architecture Framework.
This effort will also support the activities of the Federal CIO Council’s Emerging
Information Technology and Interoperability Committee and contribute to the
Committee’s near term vision, which is increased interoperability of Federal business
processes to achieve a cost-effective, value-added contribution to the efficiency of the
Federal enterprise.
Figure 13 illustrates the products selected from DoD’s Framework that will be used as
templates for populating the Federal Framework cells selected for the Pilot [Sowell,
1999]. Although, as shown previously, many more DoD products map to the FEAF cells,
only a few products were selected for a thin-thread example architecture for the Pilot.
Figure 13. DoD Framework Products Mapped to the Federal Pilot Architecture ModelsPage 16
Note that the Technical Architecture Profile does not actually map to the FEAF cells,
because “Standards” are not explicit in the FEAF’s modified Zachman Framework. It is
included here for completeness of the Pilot.
3.3 Using the DoD Framework Products with the Treasury Department’s Enterprise
Architecture Framework
On 3 January 1997 the Treasury Department published its Treasury Enterprise
Architecture Framework (TISAF) [Department of the Treasury, 1997]. At this writing,
the TISAF document is evolving to become the Treasury Enterprise Architecture
Framework (TEAF). Some of the goals for this evolution are to make the document more
user-friendly, to make it more explicit in its direction (more prescriptive rather than just
descriptive), and to make it consistent with the FEAF. To further all of these goals, the
TEAF uses the same DoD Framework products that are being used in the FEAF Pilot,
and makes those products mandatory.
The TEAF is based on an adaptation of the Zachman Framework, using essentially the
same rows (perspectives) as the Zachman Framework, collapsing the bottom two rows
into one, and modifying the columns into four “Views” as shown in figure 14.
Figure 14. The Views and Perspectives of the Treasury Enterprise Architecture FrameworkPage 17
The current draft TEAF adopts the distinction between essential and supporting products
that is used in the DoD Framework (the TEAF calls the products “work products”). The
TEAF has adopted the DoD Essential product set as a starting point, to which Treasury-
specific products may be added later. In addition, the TEAF lists many of the DoD’s
supporting products, as well as other products derived from IRS work and other sources.
Figure 15 illustrates the selected DoD products mapped to the cells of the Treasury
Framework [Department of the Treasury, 2000]. Note that this mapping is representative
and for illustration only; the TEAF document was in draft as of this writing and the exact
mapping may therefore be subject to change.
The DoD Framework allows for constructing products at multiple levels of detail, as
needed; the TEAF has accounted for this by giving each level of detail a distinct product
name. For example, the DoD’s Operational Node Connectivity Description is
represented three times in the TEAF matrix: once as Node Connectivity Description
(Conceptual), once as Node Connectivity Description (Logical), and once as Node
Connectivity Description (Physical).
Figure 15. Representative Mapping of the DoD Framework’s Products to the Cells of the TEAF
3.4 U.S. Customs Service Use of the DoD Framework Products
The U.S. Customs Service is using several of the DoD Framework’s product types in
developing an architecture description of its Automated Commercial System. This effort
is described in another CCRTS conference paper [Thomas et al., 2000].
4.0 Current Plans for Evolution of the Framework
The Office of the Assistant Secretary of Defense (C3I) is undertaking an effort to evolve
the C4ISR Architecture Framework beyond its current Version 2.0. The plan is to
develop a Version 2.1, which makes some improvements and refinements to Version 2.0,
and to develop the broad outlines for an evolution to a Version 3.0. The main objectives
in developing Version 2.1 are to
1. Widen the scope of the document from C4ISR to more explicitly address
DoD-wide application.
2. Improve on version 2.0 to leverage lessons learned and emerging tools and
methodologies. These improvements will include simplification, clarification,
and a discussion of the implications of object-oriented techniques and tools on
the Framework.
It is the intent that any architectures that are compliant with version 2.0 will also be
compliant with version 2.1 without modifications. Any major changes such as making
the Activity Model a required product will be “grandfathered” to make exceptions for
architecture efforts already underway.
Overall reaction to the C4ISR Architecture Framework, Version 2.0 guidance was quite
positive. Most organizations supported the requirement for such guidance, and the
consensus was that, if executed properly, the guidance can provide a valuable vehicle for
streamlining the architecture process as well as related processes.Page 19
Several suggestions were submitted with respect to Framework enhancements. Some of
the more significant suggestions are described in table 1. As of this writing, these are
some of the changes that are expected to appear in the draft of Version 2.1. The final
product may differ, pending working group recommendations.
Table 1. Some Version 2.1 Changes Planned Resulting from Community Feedback
Community Feedback on Version 2.0
Resulting Changes Planned for
Version 2.1
•
Remove C4ISR from the title.
•
Plan to do
•
Streamline, clarify definitions.
•
Plan to do
•
Please make the Activity Model
“Essential.”
•
Plan to do, and redesignate as “OV-2”
•
NOTE: Operational Node Connectivity
Description and Operational Information
Exchange Matrix must be renumbered
because of the insertion of the Activity
Model into the Essential product set.
•
Provide more process guidance, i.e.,
how to use the Framework.
•
Some organization-specific tailorings of
the Framework generic process will be
referenced and excerpted.
•
Provide some guidance for those of us
using object-oriented techniques.
•
Mappings to object-oriented notations
are planned.
•
Example architecture showing object-
oriented versions of products is planned.
•
Give some guidance on how to move
from “AS-IS” to “TO-BE”
architectures.
•
A Capability Maturity Profile product is
planned (AV-3).
•
Address the “value of architectures”
question.
•
A new section is planned to begin
addressing the value of architectures and
architecture metrics.Page 20
Table 1. Some Version 2.1 Changes Planned Resulting from Community Feedback – concluded
Community Feedback on Version 2.0
Resulting Changes Planned for
Version 2.1
•
The examples are confusing and too
numerous.
•
Real-world examples will be omitted in
favor of generic templates.
•
The distinction between “essential” and
“supporting” products is confusing.
Please eliminate the distinction or
change the names.
•
Will use clarified terms to emphasize the
intent – that some products are needed
for Joint analysis, integration, and reuse
and are therefore mandatory even if they
are not directly needed for the individual
architecture’s specific purpose.
•
We need more structure in the
Operational Information Exchange
Matrix, less freedom.
•
The matrix will be further detailed.
•
Clarify the connections between the
operational view and the systems view.
•
The Operational Information Exchange
Matrix and the Systems Data Exchange
Matrix (formerly called the “Systems
Information Exchange Matrix”) will be
refined and more closely related to
facilitate the transformation of
operational requirements into system
requirements.
•
Product Relationship Charts will
illustrate other relationships among the
views.
•
A “value of architectures” section is
planned to address an audit trail through
the views.
•
The Framework is too big.
•
Document will be restructured, with key
information in a relatively small body
and supplementary information in
appendices.
•
Please provide information on
automated tools (also some advice not
to get into detailed tool discussions).
•
Some general information about tool
will be provided, but no particular
commercial tools will be endorsed.
•
Please clarify that the Operational
Node Connectivity Description (OV-2)
can be used to portray “functional”
rather than physical nodes.
•
Existing words to that effect will be
supplemented with a template showing
functional nodes.
•
We need more guidance on the degree
of freedom allowed in the graphical
appearance of the product; as it is, the
Framework seems to imply that only
Structured Analysis representations
can be used.
•
Activity Model write-up will be revised
to be less IDEF0-specific.
•
A mapping of products to object-
oriented notations is planned.
•
Example architecture is planned that
illustrates object-oriented product
alternatives.Page 21
References
[Architecture Coordination Council, 1998] Memorandum, 23 February 1998, Subject:
Strategic Direction for a Dod Architecture Framework.
[Author’s Correspondence, 2000] Communication with TOGAF committee members.
[C4ISR Architecture Working Group, 1997] C4ISR Architecture Framework Version
2.0. Office of the Assistant Secretary of Defense for Command, Control,
Communications and Intelligence, Washington D.C., November 1997.
[Department of the Treasury, 1997] Treasury Information System Architecture
Framework, version 1.0. Office of the Deputy Assistant Secretary for Information
Systems and Chief Information Officer, Department of the Treasury, Washington, D.C.,
3 January 1997.
[Department of the Treasury, 2000] Treasury Enterprise Architecture Framework,
Version 1. Department of the Treasury Chief Information Officers’ Council,
Washington, D.C., July 2000 (in draft as of this writing).
[Federal CIO Council, 1999] Federal Enterprise Architecture Framework, Version 1.1.
Department of Commerce, Technology Administration, National Technical Information
Service, Springfield, VA., 1999.
[Sowell, 1999] P. Kathie Sowell. The C4ISR Architecture Framework and the Federal
Enterprise Architecture Framework. The MITRE Corporation, McLean, Virginia. 1999.
[Sowell, 1999] P. Kathie Sowell. Consolidated Mapping of C4ISR Framework Products
to Federal Framework Models. The MITRE Corporation, McLean, Virginia, 1999.
[Thomas et al., 2000] Rob C. Thomas II, Raymond A. Beamer, P. Kathie Sowell.
Civilian Application of the DoD C4ISR Architecture Framework: A Treasury
Department Case Study, 5th International Command and Control Research and
Technology Symposium, 2000.
