Anyone who has had a kitchen fitted knows the distance between a sketch on the back of an envelope and a room you can actually cook in. A TRL assessment applies that same judgement to a technology and pins a number on it, so that an engineer, a funder and a tax inspector can argue about the same thing in the same vocabulary. NASA, which created the scale, describes technology readiness levels as a measurement system used to assess the maturity of a particular technology, running across nine levels with TRL 1 the lowest and TRL 9 the highest.
Reading the nine definitions takes ten minutes. Producing a score that survives a funding panel or a tax review takes an evidence file, a written operating environment and a second opinion. What follows is the procedure run, in the order the work happens, with a check to complete before the next step begins.
What a TRL assessment settles
The assessment answers one question: how much of this technology has been shown to work in the conditions where it will be used. It is a statement about evidence, which means it is only ever as good as the documents behind it. The resulting score then feeds stage gates, investment decisions and, in some jurisdictions, tax claims. KPMG notes that Revenue's R&D Tax Credit Guidelines in Ireland treat identification of the TRL stage as a useful step in identifying qualifying R&D expenditure, and that the Revenue scale is designed for self-assessment on headings that are deliberately broad. Broad headings combined with self-assessment is the combination that produces inflated scores, which is why everything below leans on artefacts and on a second reader.
The procedure
Defining the boundary statement
Write a boundary statement before anyone scores anything. Name the technology, list the elements inside the boundary and list the interfaces outside it. A readiness level attaches to a technology at a defined boundary, and a score for a whole platform tells you nothing about the subsystem that is still a laboratory curiosity. Keep the statement to one page and have the engineering lead sign it.
You can move on when the boundary statement exists, is dated, and names what sits inside the line and what has been excluded. Anyone who cannot draw that line is not ready to score.
Operational environment impact
The environment decides which levels are reachable. The Clean Growth Hub at Innovation, Science and Economic Development Canada states in its TRL assessment tool that a TRL is only valid for the specific operational environment for which it was tested, and that a technology moving to a different environment has to be tested and refined there before it holds the same level. That single rule kills most of the optimistic scores seen, because teams routinely test on a bench and then claim readiness for a factory floor.
Set the environment down in a paragraph: temperature and humidity range, duty cycle, the users, the integration points, the supply chain, and every condition that will differ from the bench. Get the person who will operate the thing to agree it.
You can move on when a signed environment description exists and the test team has confirmed that its rigs represent it, or has written out the differences.
Assessment route options
Two routes are in common use, and the choice sets how much evidence the file will need.
- Self-assessment questionnaire: the project team scores itself against a published checklist; fast, cheap and vulnerable to optimism; eg technology reported that a common problem across projects is the varied interpretation of how far along the development roadmap a product really is, and built its diagnostic tool around that gap.
- Independent panel review: two or more assessors from outside the project score against the same checklist and then reconcile; slower, more expensive, and the version that holds up in front of a funder, a customer or a tax inspector.
You can move on once the route is recorded and the assessors, where used, are named.
Building the evidence file
Make one folder per level and fill it with dated artefacts. The Canadian tool publishes a checklist of activities to achieve each level, which gives the file its skeleton: published findings for level 1, identified applications and supporting analysis for level 2, separate components validated in a laboratory for level 3, and so on up to full operational deployment.
A photograph of a prototype is decoration. A test record with a date, a rig description and a result is evidence.
You can move on when every claimed level holds at least one artefact that a stranger could inspect.
How to score the levels
Start at level 1 and climb. The Clean Growth Hub advises erring on the side of the conservative: where there is uncertainty about whether a technology sits at a level, assign the lower one. It also draws a distinction that catches experienced teams out. A technology has achieved a level when it meets the requirements of that level and of all the levels below it. A technology is at a level when the team is currently working on the requirements of that level. Report both, in separate columns, because the first column is what a funder will check and the second is what your plan should be built on.
You can move on when the achieved column stops at the first level without an artefact and no higher level is claimed there.
Reconciling independent scores
Disagreement between assessors is information. The TRL-IS team, writing in Heliyon, adapted the scale for implementation science, tested a checklist on six real-world cases with ten raters and reported an inter-rater reliability of 0.90 on the intraclass correlation, with a 95 per cent confidence interval of 0.74 to 0.98. Their adaptation removed laboratory testing and sharpened the boundary between level 6 and level 7, which is where most arguments start. A published checklist and a documented reconciliation both raise agreement.
You can move on when the remaining differences are written down alongside the reason for the score finally chosen.
Recording the verdict and next action
Put the boundary, the environment, the achieved level, the level in progress, the evidence index and the action that lifts the technology one level onto a single page. Date it, and diarise the review.
You can move on when a reader who missed the meeting can reproduce the score from that page alone.
Where the scale bends
The scale is an ordinal judgement about evidence, and treating it as a micrometer is the fastest route to a bad decision. The Aerospace Technology Institute states on its TRL guidance page that TRL definitions can be subjective and the scale imprecise, and that the ATI Programme therefore uses them as a guideline when evaluating projects. That programme works to advance technology from level 3 to level 6, and it treats full-scale flight demonstration as closer to level 7 than level 6, with the answer depending on the technology, the system it sits in and the objectives of the demonstration.
NASA's own descriptions show how much hangs on a single word. It calls a level 8 technology "flight qualified" and a level 9 technology "flight proven", which places the whole difference between the two levels in the record of a successful mission. Read the definitions closely and you will find that most of the argument in a scoring meeting is about whether a test counted.
Sector adaptations move the wording without changing the counting. The TRL-IS paper found only 11 papers that used the TRL to evaluate readiness in health and social science implementation research, and its authors changed the scale by removing laboratory testing and limiting the use of operational environment. Two frameworks that look identical at the top of the scale can therefore disagree sharply in the middle, and a score quoted without naming the framework is close to useless.
Re-score at every gate. A TRL assessment is a snapshot of evidence on a date, and it goes stale the moment the environment changes, the design changes or the test campaign ends.
Sources
- Technology Readiness Levels - NASA
- Technology Readiness Level (TRL) Assessment Tool - Clean Growth Hub, Innovation, Science and Economic Development Canada
- Technology Readiness Levels (TRL) - Aerospace Technology Institute
- Assessment of a TRL - Technology Readiness Level for R&D - KPMG
- Adaptation of the technology readiness levels for impact assessment in implementation sciences: The TRL-IS checklist - PMC
- eg technology launch Technology Readiness Level (TRL) assessment - eg technology
