FTTI from simulation, not assumption
Client & context
The safety concept for AstaZero's Test Robot — equipment that physically drives autonomous trucks on a closed proving ground — needed defensible Fault Tolerant Time Interval (FTTI) figures for the vehicles under test.
The problem
FTTI is a cornerstone of any ISO 26262 timing argument: how long the system can tolerate a fault before a hazard occurs. Estimating it by engineering judgement leaves the weakest link in an otherwise rigorous safety case — an assessor can challenge every number.
What I did
- Built a simulation tool computing FTTI for vehicles on a closed proving ground.
- Modelled vehicle dynamics and failure-response timing per ISO 26262 — fault occurrence, detection, reaction, and transition to the safe state.
- Used the simulation results directly in the Test Robot safety concept, replacing assumption-based timing budgets with computed evidence.
The outcome
FTTI evidence derived from simulation rather than assumption, feeding directly into the safety concept and the safety-case argument for SAE L3-L4 test equipment.
Standards & tools
ISO 26262FTTIVehicle dynamicsSimulationSAE L3-L4
Facing something similar?
This is the kind of work I do under Safety Tooling & Simulation, Built to Order.
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