TRL REFERENCE GUIDE
Overview
What Technology Readiness Levels measure
Technology Readiness Levels (TRL) are a nine-point scale for grading the maturity of a technology, from the first observation of basic scientific principles through to a system proven in real operations. Each level carries a defined exit criterion that must be evidenced before a technology advances to the next. The scale runs in parallel for hardware and software, with a distinct description of what readiness looks like in each.
Discovery → Development → Deployment · lower TRL = earlier-stage, higher risk · higher TRL = closer to market
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2
3
4
5
6
7
8
9
DiscoveryTRL 1-2
Discovery / DevelopmentTRL 3
DevelopmentTRL 4-7
DeploymentTRL 8-9
For each level below, Hardware and Software describe what readiness looks like for each type of technology, and Exit criteria is the evidence needed before moving to the next level. Find the level that best matches your technology today.
DiscoveryTRL 1-2
1Basic principles observed and reported
Hardware
Scientific knowledge generated underpinning hardware technology concepts / applications.
Software
Scientific knowledge generated underpinning basic properties of software architecture and mathematical formulation.
Exit criteria
Peer-reviewed publication of research underlying the proposed concept / application.
2Technology concept and / or application formulated
Hardware
Invention begins. Practical application is identified but is speculative; no experimental proof or detailed analysis is available to support the conjecture.
Software
Practical application is identified but speculative; no experimental proof or detailed analysis available. Basic properties of algorithms, representations and concepts defined; basic principles coded; experiments performed with synthetic data.
Exit criteria
Documented description of the application / concept that addresses feasibility and benefit, or patents.
Discovery / DevelopmentTRL 3
3Analytical and experimental critical function and / or characteristic proof of concept
Hardware
Analytical studies place the technology in an appropriate context, and laboratory demonstrations, modeling and simulation validate analytical predictions.
Software
Development of limited functionality to validate critical properties and predictions using non-integrated software components.
Exit criteria
Documented analytical / experimental results validating predictions of key parameters.
DevelopmentTRL 4-7
4Component validation in a laboratory environment
Hardware
A low-fidelity system / component is built and operated to demonstrate basic functionality and critical test environments; associated performance predictions are defined relative to the final operating environment.
Software
Key, functionally critical software components are integrated and functionally validated to establish interoperability and begin architecture development. Relevant environments defined and performance in this environment predicted.
Exit criteria
Feasibility documented; test performance demonstrating agreement with analytical predictions. Documented definition of the relevant environment.
5Component validation in a relevant environment
Hardware
A medium-fidelity system / component is built and operated to demonstrate overall performance in a simulated operational environment with realistic support elements, demonstrating overall performance in critical areas. Performance predictions are made for subsequent development phases.
Software
End-to-end software elements implemented and interfaced with existing systems / simulations conforming to target environment. End-to-end software system tested in relevant environment, meeting predicted performance. Operational environment performance predicted; prototype implementations developed.
Exit criteria
Feasibility documented; test performance demonstrating agreement with analytical predictions. Documented definition of scaling requirements.
6Sub-system model or prototype demonstration in an operational environment
Hardware
A system / component prototype that adequately addresses all critical scaling issues is built and operated in a relevant environment to demonstrate operations under critical environmental conditions.
Software
Prototype implementations of the software demonstrated on full-scale realistic problems. Partially integrated with existing hardware / software systems; limited documentation available. Engineering feasibility fully demonstrated.
Exit criteria
Model or prototype documented; test performance demonstrating agreement with analytical predictions.
7System prototype demonstration in an operational environment
Hardware
An engineering unit that adequately addresses all critical scaling issues is built and operated in a relevant environment to demonstrate performance in the actual operational environment and platform.
Software
Prototype software exists with all key functionality available for demonstration and test. Well-integrated with operational hardware / software systems demonstrating operational feasibility; most software bugs removed; limited documentation available.
Exit criteria
MVP documented; test performance demonstrating agreement with analytical predictions.
DeploymentTRL 8-9
8Actual system completed and qualified through test and demonstration
Hardware
The final product in its final configuration is successfully demonstrated through test and analysis for its intended operational environment and platform.
Software
All software thoroughly debugged and fully integrated with all operational hardware and software systems. All user, training and maintenance documentation completed. All functionality successfully demonstrated in simulated operational scenarios; Verification and Validation (V&V) completed.
Exit criteria
Product validation documented; test and performance verifying analytical predictions.
9Actual system proven through successful operations
Hardware
The final product is successfully operated in an actual environment.
Software
All software thoroughly debugged and fully integrated with all operational hardware / software systems. All documentation completed. System has been successfully operated in the operational environment.
Exit criteria
Mass production documented and operational results.
Source: Adapted from the Baseload Applied Grant (BAG) Guidelines, Table 7 - Technology Readiness Level (TRL) definitions.