If you’ve ever been mid-design and asked yourself, “Do we really need full ISO 26262 compliance for this part?”—you’re not alone.
With tight timelines, evolving systems, and multiple components in play, functional safety decisions aren’t always black and white. The good news? There are three valid approaches to meeting safety goals where a component or system has safety requirements assigned—Compliance, Proven-In-Use, and Evaluated—and the smartest teams often use a mix of all three.
Let’s break them down.
Compliance:
Compliance is the most rigorous route. Full compliance means following ISO 26262 from concept to end of life, covering systematic development faults and random hardware failure coverage.
When to go this route:
- You’re building a new or novel component.
- ASIL D or fail operational applications.
- Your OEM or end-customer requires strict traceability.
The upside: You get high reliability with full systematic and random coverage in your design from the start of integration. The tradeoff? Completing the safety activities takes time, people, and a process.
Proven-In-Use: Safety by Experience
Sometimes, you don’t need to reinvent the wheel—show it’s been spinning safely for years.
Proven-In-Use (PIU) lets you leverage a component’s real-world reliability to support its use in safety applications, without redoing the full ISO26262 process. It’s especially useful for mature parts with specific applications.
To qualify as PIU:
- The part needs a documented history of safe operation.
- Usage conditions must be the same as your current application.
- Field data should show low failure rates.
It’s not about cutting corners—it’s about using existing knowledge wisely.
ASIL Evaluated: The Structured Middle Ground
This is where things get interesting. ASIL Evaluated is for components not developed under ISO 26262, but still robust enough for safety use with the right analysis.
It involves evaluating the part’s ability to meet ISO 26262 random failure targets, without claiming full systematic compliance beyond standard quality requirements.
What’s included:
- ASIL classification based on intended use.
- Fault injection testing and safety metrics (e.g., FMEDA) that can be justified.
- Clear documentation on assumptions, limitations, and a safety manual.
Where it fits:
- Commercial ICs that are already automotive-qualified.
- Off-the-shelf components reused in new safety architectures.
- Systems with external diagnostics, redundancy, or monitoring.
Establishing trust in your design rather than starting from scratch is a practical method. However, once a product has been assessed, it is crucial to acknowledge that the subsequent part in the series must adhere to a fully compliant process, given that the established safety requirements for the component have been identified.
Comparing Your Options
So Which One Should You Choose?
Ask yourself:
- Is this a new part or something we've used before?
- Do we have operational history or field data?
- Are we tight on time, resources, or budget?
- What’s our system’s ASIL target?
- Will the OEM or auditor expect full compliance?
Chances are that the right answer isn’t just one of these paths—it’s a mix. You might go full compliance for your custom power stage, ASIL Evaluated for a reused communication IC, and PIU for a resolver sensor that’s been in five previous programs.
That’s not a compromise. That’s a strategy.
What ADI Brings to the Table
Analog Devices has solutions that follow all three paths.
- Most ADI products are developed for full ISO 26262 compliance, with the safety documentation to match.
- Others are ASIL Evaluated, offering fault analysis, FMEDAs, and guidance to help you integrate with confidence.
- Proven In Use has also been successfully completed on ADI parts.
- Additionally, for standard quality-managed parts, we provide Failure Mode Distribution reports that support our customers' integration by offering necessary inputs for risk-based solutions in safety contexts.
Final Thoughts: Safety That Fits Your Design
Functional safety isn’t about checking boxes. It’s about making informed, risk-based decisions that match your product goals. Whether you're designing for ASIL D, the highest level of rigor for ISO26262, or integrating proven components into a broader architecture, there's more than one way to build a safe, reliable system.
Let’s choose the right one—together.
Read more from the Automotive FuSa blog series