An Introduction to Technology Readiness Levels (TRLs)

The National Aeronautics and Space Administration (NASA) developed Technology Readiness Levels (TRLs) in the early 70’s as a means of assessing whether emerging technology was suitable for space exploration. By the 1990’s it was in use across many US Government agencies, including the Department of Defence (DOD) and Department of Energy (DOE).  TRLs are now in common use across various funding programmes, including Innovate UK and Horizon 2020. The different levels are based on a scale from 1 to 9, with 9 being the most mature technology:

TRL 1 – basic principles observed 

TRL 2 – technology concept formulated

TRL 3 – experimental proof of concept 

TRL 4 – technology validated in lab 

TRL 5 – technology validated in relevant environment (industrially relevant environment in the case of key enabling technologies) 

TRL 6 – technology demonstrated in relevant environment (industrially relevant environment in the case of key enabling technologies) 

TRL 7 – system prototype demonstration in operational environment 

TRL 8 – system complete and qualified 

TRL 9 – actual system proven in operational environment (competitive manufacturing in the case of key enabling technologies; or in space)

Talk to the team about TRL's today

The use of TRLs enables consistent, uniform discussions of technical maturity across different types of technology. Some key messages to remember when discussing the TRL of your technology include:

TRLs are a measure of technical risk where the proposed technology is being introduced into an operating plant at the present time. Care must be taken in interpretation if the technology is being developed for introduction at a future date. TRLs, by themselves, may not always relate clearly to risk, cost and schedule. For instance, a technology at a low TRL can mature more quickly than those at higher TRLs. It is also possible that TRLs can go down as well as up if the environment of the project changes.

TRLs relate to individual plant items. They do not suggest that the individual plant items can be integrated and will work together.

TRLs do not indicate that the technology is right for the job or that application.