What does robustness mean in the context of UK SORA?

Robustness combines the safety gain provided by a mitigation with the level of assurance and integrity that the safety gain has actually been achieved.

In practice it means the CAA assesses not just what mitigations you claim, but how well you can prove they will work. High robustness typically requires independent validation or certification evidence.

For more details on SAIL levels, read our in-depth guide.