III. TRL DEFINITIONS
III. TRL DEFINITIONS
The Interim Guidebook establishes technology maturity
levels (i.e., TRLs) as the preferred descriptor of technology maturity for the
TRAs required for ACAT ID and ACAT IAM programs. Other means to accomplish a
TRA are allowed but should be coordinated in advance by the DUSD(S&T).
Using TRLs to describe the maturity of technologies considered
for a new system originated with NASA in the early 1980s. The levels ran from
the earliest stages of scientific investigation (Level 1) to successful use in
a system (Level 9), which equates to space flight for NASA. DoD has adopted
the NASA definitions—with only minor modifications—for the nine TRLs.
Having a strong grasp of the TRL concept is important. The
tables in this section give the TRL fundamentals. Table III-1 defines and
describes the DoD TRL levels. It also lists typical documentation that should
be extracted or referenced to support a TRL assignment. Table III-2 includes a
set of additional definitions that help provide a uniform interpretation of
Table III-1. TRL Definitions,
Descriptions, and Supporting Information(Source: Interim Guidebook, dated October 30, 2002)
Basic principles observed and
Lowest level of technology
readiness. Scientific research begins to be translated into applied
research and development. Examples might include paper studies of a
technology’s basic properties.
Published research that identifies
the principles that underlie this technology. References to who, where,
and/or application formulated
Invention begins. Once basic
principles are observed, practical applications can be invented.
Applications are speculative, and there may be no proof or detailed
analysis to support the assumptions. Examples are limited to analytic
Publications or other references
that outline the application being considered and that provide analysis to
support the concept.
Analytical and experimental critical
function and/or characteristic proof of concept
Active research and development is
initiated. This includes analytical studies and laboratory studies to
physically validate analytical predictions of separate elements of the
technology. Examples include components that are not yet integrated or
Results of laboratory tests
performed to measure parameters of interest and comparison to analytical
predictions for critical subsystems. References to who, where, and when
these tests and comparisons were performed.
Component and/or breadboard
validation in [a] laboratory environment
Basic technological components are
integrated to establish that they will work together. This is relatively
“low fidelity” compared to the eventual system. Examples include
integration of “ad hoc” hardware in the laboratory.
System concepts that have been
considered and results from testing laboratory-scale breadboard(s).
References to who did this work and when. Provide an estimate of how
breadboard hardware and test results differ from the expected system
Component and/or breadboard
validation in [a] relevant environment
Fidelity of breadboard technology
increases significantly. The basic technological components are integrated
with reasonably realistic supporting elements so they can be tested in a
simulated environment. Examples include “high-fidelity” laboratory
integration of components.
Results from testing a laboratory
breadboard system that are integrated with other supporting elements in a
simulated operational environment. How does the “relevant environment”
differ from the expected operational environment? How do the test results
compare with expectations? What problems, if any, were encountered? Was
the breadboard system refined to match the expected system goals more
System/subsystem model or
prototype demonstration in a relevant environment
Representative model or prototype system, which is well beyond that of TRL 5, is tested in a
relevant environment. Represents a major
step up in a technology’s demonstrated
readiness. Examples include testing a prototype in a highfidelity laboratory environment or
in [a] simulated operational environment.
Results from laboratory testing
of a prototype system that is near the desired configuration in terms of performance, weight, and
volume. How did the test environment differ
from the operational environment?
Who performed the tests? How did the test compare with expectations? What problems, if any,
were encountered? What are/were the plans,
options, or actions to resolve problems before moving to the next level?
System prototype demonstration in an operational environment
Prototype near, or at, planned
operational system. Represents a major step up from TRL 6, requiring demonstration of an actual
system prototype in an operational
environment such as an aircraft, vehicle,
or space. Examples include testing the
prototype in a test bed
Results from testing a prototype system in an operational environment. Who performed the tests? How did the
test compare with expectations? What
problems, if any, were encountered?
What are/were the plans, options, or actions to resolve problems before moving to the next
Actual system completed and qualified through test and demonstration
Technology has been proven to
work in its final form and under
expected conditions. In almost all cases, this TRL represents the end of true system development.
Examples include developmental test and
evaluation of the system in its
intended weapon system to determine if it meets design specifications.
Results of testing the system
in its final configuration under
the expected range of environmental conditions in which it will be expected to operate. Assessment of whether it
will meet its operational requirements.
What problems, if any, were encountered? What are/were the plans, options, or actions to
resolve problems before finalizing the
Actual system proven through successful mission operations
Actual application of the
technology in its final form and
under mission conditions, such as those encountered in operational test and evaluation. Examples include using the system
under operational mission
Operational test and evaluation
Table III-2. Additional Definitions of
TRL Descriptive Terms(Source: Interim
October 30, 2002)
that provide a representation of a system/subsystem and that can be used
to determine concept feasibility and to develop technical data. Typically
configured for laboratory use to demonstrate the technical principles of
immediate interest. May resemble final system/subsystem in function
||Addresses form, fit,
and function. High-fidelity laboratory environment would involve testing
with equipment that can simulate and validate all system specifications
within a laboratory setting.|
||A representative of
the component or system that has limited ability to provide anything but
first-order information about the end product. Low-fidelity assessments
are used to provide trend analysis.|
||A functional form of
a system, generally reduced in scale, near or at operational
specification. Models will be sufficiently hardened to allow demonstration
of the technical and operational capabilities required of the final
addresses all the operational requirements and specifications required of
the final system to include platform/packaging.|
||A physical or virtual
model used to evaluate the technical or manufacturing feasibility or
military utility of a particular technology or process, concept, end item,
that simulates the key aspects of the operational
(1) a real environment that can simulate all of the operational requirements and specifications required of
the final system or (2) a simulated
environment that allows for testing of a virtual prototype; used in either case to determine whether a
developmental system meets the operational
requirements and specifications of the
Software is likely to be an important element in many TRAs.
Since the TRL definitions in Table III-1 reflect a systems approach in which
software is treated as a part of a component or system, software TRLs are not
spelled out specifically in these definitions. However, because some
guidelines would be useful in determining the TRLs of the software parts of
components and systems, Appendix G
provides a set of software TRL definitions developed by the
The TRL definitions in Table III-1 are not readily applied to
medical-related items, specifically drugs, vaccines, and medical devices.
Their development and use must adhere to Food and Drug Administration (FDA)
statutes and policy and to DoD statutes and policy. The Army, in recognition
of this situation, took the initiative to establish biomedical TRLs Appendix H
provides the excellent result of their efforts.
25 According to the Interim
Guidebook, Appendix 6 of that guidebook “lists the various technology
readiness levels and descriptions from a systems approach
for both HARDWARE and SOFTWARE. DoD Components may provide
additional clarifications for Software.”