Hazard Analysis

Applicable Phases

• Primary: Phase A/B (hazard identification), Phase C (control definition)
• Supporting: Phase D (safety review for launch readiness)

Safety Assessment Workflow

1. Hazard Identification

• Categories: Fire, Explosion, Collision, Toxicity, Pressure Release, Battery Thermal Runaway, Debris Generation, RF Radiation, Contamination.
• Top-down: Start with the undesirable event (e.g., "Loss of spacecraft") and work backward to causes using fault tree logic.

2. Risk Ranking

• Severity: Catastrophic (loss of life/mission), Critical (major subsystem loss), Marginal (degraded mission), Negligible (minor impact).
• Likelihood: Frequent, Probable, Occasional, Remote, Improbable.
• Risk Index: 5×5 matrix position (e.g., 1A = Catastrophic-Frequent = unacceptable).

3. Hazard Controls & Inhibits

• Controls: Design features or operational procedures to mitigate hazards.
• Inhibits: For catastrophic/critical hazards, define independent safety inhibits (e.g., "Two-fault tolerant" for crewed missions, "Single-fault tolerant" for uncrewed).
• Requirement traceability: Every control MUST be traced to a requirement in requirements-manager.

4. Integration with Reliability

• Input: Check reliability-assessment FMECA outputs — failure modes become "Causes" in hazard reports.
• Feedback: Hazard controls may drive new reliability requirements (e.g., redundancy).

Output Format

1. Hazard Report (hazard_report.md): Hazard ID, Description, Causes, Risk Index (Before/After Control), Controls, Verification Method.
2. Safety Control Matrix (controls.csv): Summary for tracing to requirements and test plans.

Interface

• Reads from: /requirements/, /analysis/reliability-assessment/ (FMECA failure modes)
• Writes to: /analysis/hazard-analysis/
• Consumed by: requirements-manager (new safety requirements), v-and-v-manager (verification of controls)