Safety-critical standards (blueprint)
Purpose: Guidance on safety-critical engineering standards and their impact on software development practices. Each standard entry covers scope, safety integrity levels, required activities, and engineering constraints.
Guide · Updated · Source
Why functional safety is non-negotiable: For systems where failure can harm people or the environment, process and evidence matter as much as code. Standards such as IEC 61508 and ISO 26262 define lifecycle activities, independence, and integrity levels so claims about risk reduction are auditable. Skipping them shifts unbounded liability to the organization and blocks market access in regulated domains. Align blueprint reading with Embedded / IoT engineering body of knowledge for real-time and firmware context, and Embedded / IoT ↔ SDLC ↔ PDLC bridge for certification impact on phases.
Audience: Teams adopting Embedded / IoT Engineering for safety-critical applications; project-specific safety documentation stays in docs/safety/.
Safety standard family (conceptual)
Safety standards reading path
How teams move from harm-aware context to a governed standard deep dive with auditable lifecycle evidence.
- Process flowConceptual map for navigating this safety standards index.
- StartBegin when failure could harm people, property, or the environment.
- Core steps (see walkthrough below)Match the domain to a standard and open its deep dive.
- OutcomeClear scope, integrity level, and phase activities for reviewable delivery.
- Note: IEC 61508IEC 61508 supplies cross-domain functional-safety vocabulary.
Process flow
Start
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v
Core steps (see walkthrough below)
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v
Outcome
Note: IEC 61508| Standard | Domain | Focus | Deep dive |
|---|---|---|---|
| IEC 61508 | General | Functional safety of E/E/PE safety-related systems — SIL 1–4, V-model, failure modes | IEC 61508: Functional Safety of Electrical/Electronic Systems |
| ISO 26262 | Automotive | Road vehicle functional safety — ASIL A–D, HARA, HSI, FMEA, production | ISO 26262: Road Vehicles — Functional Safety |
| DO-178C | Aerospace | Software considerations in airborne systems — DAL A–E, objectives, verification, tool qualification | Embedded / IoT engineering body of knowledge |
| IEC 62304 | Medical devices | Medical device software lifecycle — safety classes A/B/C, risk management integration, maintenance | Embedded / IoT engineering body of knowledge |
| MISRA C / C++ | Coding standards | Safe subset of C/C++ for critical systems — rule categories (mandatory, required, advisory), deviation process | EMBEDDED-IOT.md §2 |
| EN 50128 | Railway | Railway software — SIL allocation, coding standards, formal methods, independent verification | Embedded / IoT engineering body of knowledge |
For each standard, guides cover: - Scope and applicability criteria - Safety integrity / assurance levels and their engineering implications - Required activities by SDLC phase (analysis, design, coding, testing, traceability) - Tool qualification requirements - Common pitfalls and practical guidance
Core knowledge: Embedded / IoT engineering body of knowledge — real-time systems, firmware development, safety engineering competency.
Bridge: Embedded / IoT ↔ SDLC ↔ PDLC bridge — safety certification impact on lifecycle phases.
Keep project-specific safety documentation in docs/safety/ and hazard analyses in docs/security/, not in this file.