Skip to content

STPA-Pro safety analysisΒΆ

nous uses STPA-Pro (System-Theoretic Process Analysis, Leveson 2023) as its safety analysis method. STPA treats safety as a control problem: losses are emergent from inadequate control rather than from component failure alone.

The artefacts follow the canonical numbered layout:

File Contents
01-purpose.md Why we are running an STPA on the simulator.
02-system-boundary.md What is inside the system, what is outside.
03-losses.md Top-level losses (L-1 .. L-4).
04-hazards.md Hazardous system states (H-1 .. H-7).
05-safety-constraints.md Safety constraints derived from hazards.
06-control-structure.md The control diagram (mermaid).
07-unsafe-control-actions.md UCA table per controller.
08-loss-scenarios.md Loss scenarios for the chosen UCAs.
09-derived-requirements.md Requirements that flow back into the backlog.

The STPA is treated as a work in progress; the v0.1 pass covers the top losses, hazards, control structure, and a first pass at unsafe control actions and loss scenarios. Derived requirements are partial and cross-link to the backlog (docs/backlog.md) and any governing ADR.