Technology readiness levels (TLRs) are a quick way to determine how mature a given technology, process, or concept is.
Technology readiness level description
- TRL 1 – Basic principles observed and reported
- TRL 2 – Technology concept and/or application formulated
- TRL 3 – Analytical and experimental critical function and/or characteristic proof-of-concept
- TRL 4 – Component and/or breadboard validation in laboratory environment
- TRL 5 – Component and/or breadboard validation in relevant environment
- TRL 6 – System/subsystem model or prototype demonstration in a relevant environment
- TRL 7 – System prototype demonstration in a space environment
- TRL 8 – Actual system completed and “flight qualified” through test and demonstration
- TRL 9 – Actual system “flight proven” through successful mission operations
Technology readiness levels can be used to describe a system and each of its subsystems. And the subsystem’s subsystems. All the way down to the individual components. The same goes for processes.
Materials and Processes for Spacecraft and High Reliability Applications (www.springer.com/cda/content/document/cda_downloaddocument/9783319233611-c2.pdf), page 10