TARA and HARA are often discussed together because modern automotive systems combine safety-critical behavior with connected, software-driven architectures. But they answer different questions. HARA asks what hazardous events can result from malfunctioning behavior. TARA asks what cybersecurity threats can compromise assets and cause damage.
HARA in one sentence
HARA supports ISO 26262 functional safety by identifying hazardous events, rating severity, exposure, and controllability, deriving ASIL, and defining safety goals. It is centered on malfunctioning behavior and unreasonable safety risk.
TARA in one sentence
TARA supports ISO/SAE 21434 cybersecurity engineering by identifying assets, damage scenarios, threat scenarios, attack paths, attack feasibility, impact, risk treatment, cybersecurity goals, and requirements. It is centered on malicious or unauthorized compromise of cybersecurity properties.
Where they overlap
TARA and HARA overlap when cybersecurity compromise can contribute to safety-relevant behavior. For example, unauthorized modification of a vehicle control parameter may become both a cybersecurity risk and a safety-relevant concern. The disciplines remain distinct, but the evidence should be connected.
Key differences
Starting point. HARA starts from item behavior and operational situations. TARA starts from assets, cybersecurity properties, and damage scenarios.
Risk logic. HARA uses severity, exposure, controllability, and ASIL. TARA evaluates attack feasibility, impact, and risk treatment according to the cybersecurity process.
Outputs. HARA produces safety goals and safety requirements. TARA produces cybersecurity goals, requirements, controls, claims, and evidence needs.
Review expertise. HARA needs functional safety expertise. TARA needs cybersecurity expertise. Shared review matters where safety and security interact.
Why one platform helps
Separate spreadsheets and documents make it hard to see how safety and security decisions affect each other. Aegis SafeForge supports both HARA and TARA so teams can connect hazards, threats, goals, requirements, controls, evidence, and review history in a shared workflow.
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If you want to see the deterministic ASIL recomputation in action on one of your own item definitions, we are currently opening 5 design partner slots with 12 weeks of free access in exchange for product feedback.
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