Technology Readiness Levels

NASA’s Framework for Knowing How Ready Your Technology Actually Is

NASA developed Technology Readiness Levels in the 1970s to answer a deceptively simple question: how close is this technology to being ready for a real mission? The framework gives you a 1-to-9 scale that tracks progress from “we think this might work in theory” all the way to “it’s been proven in operation.”

I got interested in TRLs because I kept seeing the same problem in startups: teams would confuse a working prototype with a production-ready system, or investors would treat a research breakthrough as if it were ready to ship. TRLs give you a shared vocabulary for talking about technology maturity without the hand-waving.

The Complete Framework

Start with NASA Technology Readiness Levels for the full overview of the framework, its history, and how the nine levels work. This gives you the foundation for everything else in the series.

The Stages in Depth

The series breaks the TRL scale into three natural groupings, each with its own challenges and milestones:

TRL 1-3: Concept to Proof-of-Concept covers the early stages where you’re moving from basic research and scientific principles to initial experimental validation. This is where most ideas live and die.

TRL 4-5: Laboratory and Relevant Environment Validation is the awkward middle where your technology works in the lab but hasn’t yet proven itself in realistic conditions. These stages are where a lot of startups get stuck.

TRL 6-9: From Prototype to Operational System covers the final push from demonstrated prototype to fully operational, flight-proven system. The engineering challenges here are less about “does it work?” and more about reliability, scale, and integration.

Applying TRLs to Software

The original TRL framework was designed for hardware and space systems, so applying it to software requires some adaptation. NASA Technology Readiness Levels: A Software Development Perspective maps the framework to software-specific milestones and challenges.

Adapting TRLs for Software Development takes this further with a practical guide for embedding TRL thinking into sprint cycles and agile workflows. If you’re running a software team, this is probably the most directly useful piece in the series.

TRLs in Context

No framework exists in isolation. TRL vs Other Maturity Models compares TRLs against other approaches like MVP, Lean Startup, and various industry-specific maturity models. Understanding where TRLs fit relative to these other tools helps you pick the right framework for your situation.