TRL 1 to 9: How to Measure Your Technology's Readiness, and How Investors Read It

01Why TRL now decides who gets funded

Technology Readiness Level (TRL) used to be engineering jargon. In India it now decides funding. The government's Research, Development and Innovation Fund (RDIF), set up under a ₹1 lakh crore scheme, only finances projects at TRL 4 or above. In our experience, most Indian venture capital wants to see something closer to TRL 7 before it writes a serious cheque.

If you cannot say which level you are at, with evidence, you will be priced as if you are lower.

The scale itself is simple. NASA developed it in the mid-1970s. It was formally defined in 1989 with seven levels, and the nine-level scale used today dates from 1995. It runs from a scientific idea at TRL 1 to a system proven in real operation at TRL 9.

In December 2025 the Office of the Principal Scientific Adviser (PSA) released India's own version for public consultation. It is the National Technology Readiness Assessment Framework (NTRAF), developed with the Confederation of Indian Industry (CII), so that researchers, founders, investors and government can use one yardstick. For each level, this guide sets out what it means, what evidence proves it, and how an investor reads you when you are there.

03The nine levels, one by one

Each level answers one question: what has been proven, and where. Investors care less about the number than about which risk is left. Level names, test questions and evidence documents below follow NTRAF, which the section after the levels explains.

For each level you get the plain meaning, the question NTRAF asks, what you must show and the document that proves it. Then come sector examples, the risk still left, our read of how investors see you, and what it takes to move up. The drug and software examples follow NTRAF's sector annexures where they cover that level. The battery and drone examples are ours.

TRL 1: Basic principles observed

Someone has observed a scientific effect and written it down. There is no application yet, only knowledge, and research is just starting to move from pure science toward applied work.

NTRAF's question here is "Have basic principles been observed and reported?" You must show a research hypothesis, the principles observed, and the stakeholders identified, such as the sponsor and funding source. That stakeholder item is a programmatic criterion, and NTRAF marks it critical, so critical programmatic criteria start at this first level. The evidence document is a research observation report with a literature review and findings.

Examples include a new catalytic behaviour in a material, a biological pathway linked to a disease, or a new class of algorithm described mathematically. The risk left is everything, because nobody yet knows whether the effect can be used.

Investors will not take equity at this level. This is grant territory: the Anusandhan National Research Foundation (ANRF), the Departments of Science and Technology (DST) and Biotechnology (DBT), universities and philanthropies. To reach TRL 2, propose a specific practical application and argue on paper that it could work.

TRL 2: Technology concept formulated

A practical use of the principle has been invented, but only on paper. Claims are speculative and untested.

The NTRAF question is "Has the technical solution for the system or process been formulated?" You must show the target application, paper studies showing feasibility, a design solution and documented performance predictions. A first, qualitative list of risk areas completes it. The evidence document is a technical solution formulation document with architecture, design and diagrams.

Think of a battery chemistry modelled on paper, a drug target with a proposed mechanism, or a software architecture with its core algorithm specified. What can still go wrong is that the concept may not survive contact with an experiment.

You are pre-investable. Some specialist angels or university-linked funds engage on an exceptional team, betting on people more than technology. A provisional patent filed here protects you later. To reach TRL 3, run the first experiments or simulations that test the critical function.

TRL 3: Experimental proof of concept

Active R&D has started. Lab experiments or simulations show the critical function works, one piece at a time.

NTRAF asks, "Has proof of concept been demonstrated in a simulated environment?" You must show predictions validated by analysis or experiment, and lab experiments that verify feasibility. Add defined performance metrics, a first study of cross-technology effects, components tested at lab scale and a customer representative identified. The evidence document is a simulation or proof-of-concept report covering method, data, results and conclusions.

A single cell hits its target energy density in a lab rig. A drug candidate shows in vitro and early in vivo proof of concept. Working code runs the core algorithm on test data. The pieces work alone but may not work together, and lab results may not repeat.

This is the earliest point where deep-tech pre-seed funds and university-linked funds lean in. Valuations are low and dilution high. Investors diligence IP ownership hard, especially for university spin-outs, so get the assignment or licence done now. To reach TRL 4, integrate the components into a single working breadboard and test them together.

TRL 4: Component and/or system validated in the lab

The components now work together as a basic integrated system, a breadboard or rough prototype, in the lab. NTRAF calls TRL 4 to 6 the bridge from science to engineering.

The NTRAF question is "Has the component or system been validated in a lab?" You must show available components assembled into a breadboard, with lab experiments showing they are compatible. Cross-technology issues must be identified, with a preliminary failure mode and effects analysis (FMEA) or risk analysis. An Integrated Product Team, the cross-functional group that owns development, must be formally set up with a charter.

This is also the first level where NTRAF marks manufacturing criteria as critical, with items such as pre-production parts, breadboard assembly and key manufacturing processes. The evidence document is a component or system validation report.

A multi-cell battery module cycling on a lab bench is at TRL 4. So is a drug with animal-model efficacy and early toxicology run outside good laboratory practice rules (non-GLP). So is software running with limited functionality on representative data in a controlled setup. The lab is forgiving, and real inputs, temperatures, loads and users have not been tested yet.

This is the floor for RDIF capital and the start of serious seed interest from deep-tech funds. The questions shift to how far you are from a real environment, and what it will cost to get there. Have your FMEA and a costed path to TRL 6 ready. To reach TRL 5, move from a breadboard to a higher-fidelity prototype with realistic interfaces, and test it under simulated real conditions.

TRL 5: Lab-scale prototype validated in a relevant environment

A higher-fidelity, lab-scale prototype is tested with realistic supporting elements in conditions that simulate real use. The prototype starts to look like the product.

NTRAF asks, "Has the laboratory-scale prototype been validated in a relevant environment?" You must show high-fidelity lab integration with realistic interfaces, a brassboard that is closer to final form than a breadboard. Cross-technology effects are analysed, and form, fit and function are reviewed with end-user staff. Draft systems engineering and test plans exist, and pre-production hardware is available. The evidence document is a laboratory-scale prototype validation report.

A battery pack goes through simulated drive cycles and temperature extremes. A drug completes efficacy and toxicology studies under good laboratory practice (GLP), and the Drugs Controller General of India (DCGI) approves the start of Phase 1. Software is integrated with existing systems and through alpha testing. The risk left is scale: a lab-scale prototype may not survive an engineering-scale build, and costs are still estimates.

You are at seed to pre-Series A. Expect questions on bill of materials, unit economics and early customers. A design partner or letter of intent carries real weight. To reach TRL 6, build an engineering- or pilot-scale prototype and demonstrate it outside the lab, with a customer involved.

TRL 6: Engineering or pilot-scale prototype in a relevant environment

This is the jump from lab scale to engineering scale. A representative prototype works as a whole in a realistic environment outside the lab. Most of the valley-of-death failures we see happen on the way here.

The NTRAF question is "Has the engineering or pilot-scale prototype been demonstrated in a relevant environment?" You must show a representative prototype tested in a high-fidelity or simulated operational environment, with engineering feasibility demonstrated. Critical manufacturing processes must be prototyped. NTRAF also asks for an end-user transition agreement, a final technical report, and a transition plan with a business case. The evidence document is an engineering or pilot-scale prototype demonstration report.

A pilot battery line produces modules that are tested in a customer's vehicle. A drug has pilot lots made under good manufacturing practice (GMP) and is in Phase 1 clinical trials. Software passes full-scale feasibility, end-to-end validation and beta testing with real users. The science question has been answered, so the risk left is engineering and manufacturing. Can it be built repeatably, at cost, and certified?

This is Series A territory for deep-tech specialists. Venture debt and RDIF-backed loans become workable because the remaining risk is engineering and scale. NTRAF's requirement for a transition agreement and business case is exactly what an investor asks for. To reach TRL 7, build a full-scale prototype representative of production and run it in the real operating environment.

TRL 7: Full-scale prototype demonstrated in an operational environment

A full-scale prototype, at or near the planned final system, runs in the actual environment where it will be used, typically with a real customer.

NTRAF asks, "Has the full-scale system prototype been demonstrated in a relevant operational environment?" You must show a fully integrated prototype demonstrated in an actual or simulated operational environment, built from components representative of production. Materials and processes must be initially demonstrated, and you must be ready for low-rate initial production. Safety and adverse-effect issues must be identified and mitigated. The evidence document is a full-scale prototype demonstration report with performance metrics.

Examples are production-intent battery packs in customer field trials, or a drug in Phase 2 clinical trials. Software goes through third-party testing: independent verification, security audits and interoperability checks. The risk left is market and manufacturing. Will customers buy at the price, and can production yields hold?

In our experience this is the point where most generalist Indian VCs get comfortable. Diligence moves from technology to market: pipeline, pricing, gross margin, manufacturing partners and certification path. To reach TRL 8, freeze the design, qualify it through formal testing and certification, and prove manufacturing yield.

TRL 8: System complete and qualified

The final product is built in its final form, qualified against specification and proven under expected conditions. NTRAF calls this the end of true system development.

The NTRAF question is "Has the actual system operated successfully in a limited operational environment?" You must show the system qualified through test on the actual platform and meeting specifications, with form, fit and function shown in the operational environment. Manufacturing yield and producibility must be demonstrated, materials must be in production, and you must be ready for full-rate production. The evidence document is a limited operational environment testing report.

Battery packs certified to BIS, AIS or IEC standards ship against first orders. A drug completes Phase 3 and wins approval of its new drug application (NDA). Software is assessed against ISO/IEC quality standards, audited for privacy and launched to market. The risk left is commercial scale, where working capital, supply chain and sales execution now dominate.

The money here is growth equity, larger Series B and C rounds, strategic investors and bank debt. The conversation is order book, capacity, working capital and margins. To reach TRL 9, operate the system across the full range of real conditions, at scale, over time.

TRL 9: Proven in operational use

The product is in routine operational or commercial use across the full range of conditions it was designed for, with a track record.

NTRAF asks, "Has the actual system operated successfully over the full range of conditions in the operational environment?" You must show the system working as defined in its operating concept, deployed in its intended environment, with operational test and evaluation complete. Manufacturing is controlled to quality standards, with stable production and a stable design. Documentation is complete and a training plan is in place. The evidence document is an operational environment testing report.

Battery packs are in fleet use with warranty and field-failure data. A launched drug runs Phase 4 post-approval studies. Software is in production with monitoring, continuous improvement and regulatory change management. Technology risk is gone, and execution, competition and market risk remain.

You are valued like any operating business, on revenue, margins, growth and cash flow. The buyers are private equity, growth funds, strategics and eventually public markets. What comes next is the next product. Mature companies run a portfolio of critical technologies at different TRLs, and that is where RDIF-backed project finance for new R&D fits again. The Technology Development Board's first RDI round included listed companies such as Tejas Networks and Ather Energy.

05How to measure your TRL

Your TRL is the highest level for which you hold documented evidence. The level you expect to reach next quarter does not count. Measure it the way an investor's technical diligence team would.

1. Run an NTRAF self-assessment. List your critical technology elements and take each through Levels 0, 1 and 2. Certify a level only where every critical criterion has a document behind it. Use TRL Compass if you want an assessment certificate to show funders.
2. Rate each critical subsystem separately. A drone can have a TRL 8 airframe and a TRL 4 sensor. Investors will find the weakest link and read your readiness from it, so name it first.
3. Build an evidence file per level. For every level you claim, keep the test protocol, the raw data, the test environment, who ran it and the date. Third-party or customer-run tests count for far more than internal ones.
4. Score manufacturing and commercial readiness beside TRL. NTRAF already folds manufacturing and programmatic criteria into its levels. In our experience, investors increasingly ask for separate manufacturing and commercial readiness scores.

Treat CRL as an investor's lens, since NTRAF has no commercial readiness scale. A company at TRL 7 with MRL 3 and no customers is riskier than its TRL suggests. One at TRL 5 with signed design partners and a manufacturing partner may be a better investment than its TRL suggests.

07Five mistakes that cost founders credibility

Investors discount an inflated TRL claim harder than an honest low one.

In our experience, these are the claims that unravel in diligence.

1. Rounding up. A demo that worked once does not make TRL 6. One successful run is an anecdote; repeatable data is a level.
2. Confusing the lab with the field. A "relevant environment" means real conditions: real temperatures, real data, real users. A controlled office test is still TRL 4.
3. Rating the product by its best part. Investors will read your TRL as your weakest critical subsystem's. Say so before their engineer finds it.
4. Treating TRL as the whole story. TRL 7 with no manufacturing path and no paying customer is not a Series A company. Pair TRL with manufacturing and commercial readiness.
5. Skipping the paper trail. If the evidence lives in someone's head or on a WhatsApp thread, it does not exist for diligence.

09Frequently asked questions

What are TRL levels 1 to 9?

They are a nine-step scale for how far a technology has been proven, from basic principles observed (TRL 1) to a system proven in operational use (TRL 9). NASA developed the scale in the mid-1970s. It was formally defined in 1989 with seven levels, and the nine-level version dates from 1995. India's NTRAF uses the nine levels.

What is TRL 4?

At TRL 4 the components work together as a breadboard or rough prototype, validated in a lab. RDIF reads it as having "at least achieved laboratory-level prototypes", and it is the lowest level RDIF will finance. RDIF asks for no TRL certificate, and its fund managers can refer to NTRAF when they judge it.

How do you determine a technology's TRL level?

List your critical technology elements and assess each one separately against NTRAF. A short pre-screen puts each element in a band, a top-level question per level gives the anticipated TRL, and a detailed criteria check confirms it. If any critical criterion lacks a document, the element drops a level and the check repeats. TRL Compass runs this online and issues a certificate.

What is the difference between TRL and MRL?

TRL asks whether the technology works, and in what environment. MRL, the US Department of Defense's manufacturing readiness scale, asks whether you can make it repeatably at a target cost. NTRAF tags manufacturing criteria inside its TRL levels, and its first critical manufacturing criteria come at TRL 4.

What is NTRAF, India's technology readiness framework?

The National Technology Readiness Assessment Framework is the Office of the PSA's method for rating technology readiness, developed in consultation with CII. It was unveiled in December 2025 for public consultation. As of October 2026 the PSA's page still presents it as a consultation draft, and it has run as the TRL Compass platform since 29 June 2026. It rates each critical technology element against Technology, Manufacturing and Programmatic/Quality criteria.