This framework defines the minimum set of governance, engineering and evidentiary requirements that an organisation shall satisfy in order to deploy, operate, study or rely on artificial intelligence systems in a manner that is accountable, auditable and defensible. The central premise is unchanged from the framework it supersedes. Artificial intelligence systems are not autonomous decision makers. They are a supervised, constrained and auditable processing layer that accelerates human cognitive work without substituting human accountability. To that premise this edition adds a second one, which governs everything in the evidence domain. A statement produced by, or about, an artificial intelligence system is not established because the system produced it, because a metric improved, or because a demonstration was persuasive. It is established when a documented procedure exists under which the statement could have failed and did not.