Title: Functional Safety Concept | ISO 26262 Academy URL: https://iso26262.academy/features/concepts/functional-safety-concept Description: Learn how to derive safety goals, define safe states, and build functional safety requirements from HARA results. --- Concept guide · ISO 26262-3 §7 · 13 chapters # Functional Safety Concept Turn HARA safety goals into a complete functional safety concept: safe states, fault reactions, degradation strategies, and FSR development - taught with synchronized video, interactive diagrams, and a complete ESC case study. 13 Chapters 9 Interactive diagrams 1 Case study 2h Video Included in Free Pro Expert [Start learning](https://iso26262.academy/register?plan=free&from=%2Fconcepts%2Ffunctional-safety-concept&utm_source=website&utm_medium=cta&utm_campaign=features_concepts) See the chapters Course intro · 2 min Free preview A 2 min look inside the course. 2 hours of course videos for registered users. The short version ## Quick answers What is a functional safety concept in ISO 26262? The functional safety concept (FSC) is the vehicle-level safety strategy required by ISO 26262-3 Clause 7. It derives functional safety requirements (FSRs) from the safety goals produced by the HARA and specifies how the item detects faults, reacts to them, warns the driver, and reaches or maintains a safe state within the fault tolerant time interval. It also defines degradation strategies, operating modes, and the allocation of FSRs to the preliminary architecture. The FSC is the bridge between hazard analysis and the technical safety concept, and every later safety requirement traces back to it. What is the difference between the FSC and the TSC? The functional safety concept works at the vehicle function level: it states what the system must do to stay safe - detect faults, warn the driver, degrade gracefully, reach a safe state - without prescribing the implementation. The technical safety concept (TSC), developed in the ISO 26262-4 system phase, translates those functional safety requirements into technical safety requirements for a concrete architecture: which sensor, which monitoring mechanism, which diagnostic coverage, which hardware-software interface. The course ends by handing you off to the TSC with the traceability structure already in place. Keep going, free - [Article · 7 min read Functional Safety Concept Guide: 7 Expert Tips for Success](https://iso26262.academy/blog/functional-safety-concept-guide-7-expert-tips-for-success) - [Demo exam · no account Test yourself with 7 exam-style questions](https://iso26262.academy/demo-exam) A practical sample · no account needed ## What does a functional safety concept do? A functional safety concept translates safety goals into functional safety requirements and allocates them to the preliminary architecture. It explains the required safety behavior before detailed technical implementation. An electric drive can deliver unintended torque. A safety goal calls for preventing hazardous unintended acceleration. Should the first requirement name a particular microcontroller, or describe the behavior needed to control the hazard? **Reveal the reasoning** Describe the required behavior first: for example, detect an unintended torque request and transition to a defined safe state within the time required by the hazard analysis. The technical safety concept then develops the implementation. The safe state and timing need project-specific justification. Illustrative learning example, not a project assessment. ISO 26262, Part 3 · [About the academy](https://iso26262.academy/about) This example is public. A free account gives you access to the full videos for this topic; the written guide follows the plan access shown above. Why this course · ISO 26262, Part 3, Clause 7 ## Why it pays for itself ### From safety goals to real requirements The step-by-step process chapters show how to turn HARA safety goals into a complete, allocated FSR set - with the traceability matrix that proves nothing was dropped along the way. ### Timing budgets that survive review FTTI, FDTI, FRTI, FHTI, and EOTTI are where FSC reviews get uncomfortable. The interactive timing model with ESC example values teaches you to build budgets you can actually defend. ### A complete free course with video This is the free flagship concept: all 13 chapters, 9 interactive diagrams, and 2 hours of scroll-synchronized video are available with a free account, so you can evaluate the platform on a full course. After the course ## What you’ll be able to do ### Derive safety requirements Turn HARA safety goals into complete, verifiable functional safety requirements with correct attributes and clean allocation. ### Define safe states and timing Design safe states, degradation modes, and warning concepts, and calculate FTTI/FDTI timing budgets that hold up in review. ### Build fault-tolerant architectures Apply redundancy patterns, voting schemes, and CCF prevention to meet the integrity and availability needs of high-ASIL systems. ### Write a complete FSC document Structure and deliver a real FSC with full traceability from safety goals to FSRs, using the ESC case study as your template. The curriculum · 13 chapters ## Chapter by chapter 1. 01 **What and How to Develop a FSC** Understand what a functional safety concept is, its purpose and key components, and its critical position in the ISO 26262 V-model between the HARA and the technical safety concept. - V-Model diagram - FSC definition - Key components 2. 02 **Step-by-step Process** Follow a systematic, iterative process from safety goals to a complete set of functional safety requirements, with a process flow diagram, input/output mapping, and iteration guidance. - Process flow diagram - Input/output mapping - Iteration guidance 3. 03 **Technical Foundations** Master the ISO 26262 timing model including FTTI, FDTI, FRTI, FHTI, and EOTTI with interactive diagrams, plus operating modes and precise safe state definitions. - Timing model diagram - Operating modes - Safe state definitions 4. 04 **Fault Avoidance & Tolerance** Learn fault avoidance, fault tolerance, and fail-operational versus fail-safe strategies, including redundancy patterns, voting schemes, and common cause failure prevention for safety-critical systems. - Redundancy patterns - Voting schemes - CCF prevention 5. 05 **Warning & Degradation Strategy** Design effective driver warning systems and graceful degradation strategies for fault conditions, covering warning levels, the degradation timeline, and realistic driver takeover expectations. - Warning levels - Degradation timeline - Driver takeover 6. 06 **FSR Allocation & Architecture** Allocate functional safety requirements to preliminary architecture elements with proper ASIL allocation and decomposition, interface requirements, and an interactive system architecture diagram. - Architecture diagram - ASIL allocation - Interface requirements 7. 07 **Traceability Matrix** Establish complete traceability from safety goals through functional safety requirements to implementation and verification, with traceability patterns, coverage analysis, and gap identification. - Traceability patterns - Coverage analysis - Gap identification 8. 08 **External Measures & Technologies** Integrate external safety measures, SEooC interfaces, and technology-specific considerations, including external dependencies and how technology choices influence the shape of your functional safety concept. - SEooC integration - External dependencies - Technology assessment 9. 09 **Verification & Validation** Plan and execute verification activities that confirm FSC completeness, consistency, and correctness, using review checklists, suitable verification methods, and the evidence your assessor expects. - V&V methods - Review checklists - Evidence requirements 10. 10 **Common Pitfalls** Avoid common FSC development mistakes with real-world examples, recurring anti-patterns, and corrective actions, so your concept survives reviews and functional safety assessments the first time. - Anti-patterns - Case studies - Prevention strategies 11. 11 **Best Practices & Tips** Apply industry best practices for efficient, compliant, and maintainable FSC development, including pro tips, efficiency techniques, and quality guidelines collected from real safety programs. - Pro tips - Efficiency techniques - Quality guidelines 12. 12 **Practical Example** Work through a complete ESC (Electronic Stability Control) functional safety concept from start to finish, from safety goals and safe states to a complete, traceable FSR set. - ESC case study - Complete FSR set - Real-world application 13. 13 **Expand Your Knowledge** Access related ISO 26262 processes, work product templates, and knowledge tests to consolidate what you learned and continue into the technical safety concept phase. - Related processes - Templates - Knowledge tests Interactive diagrams ## Not just text: the visual toolkit ### V-Model diagram Interactive visualization showing the FSC position in the ISO 26262 development lifecycle with clickable stages. ### Timing model diagram Animated FTTI, FDTI, FRTI, and FHTI timeline with ESC example values and timing scenarios. ### Operating modes state machine Interactive state machine showing mode transitions: initialization, normal, degraded, emergency, and off. ### Safe state flow diagram Flowchart illustrating safe state transitions with static and dynamic safe state examples. ### Functional redundancy diagram Visual representation of redundant functional paths and single-fault tolerance architecture. ### Architecture diagram ESC system architecture view showing FSR allocation to elements and interface definitions. ### CCF prevention diagram Common cause failure analysis and prevention strategies visualization. ### Degradation timeline Timeline showing a graceful degradation sequence with warning escalation. ### FFI zones diagram Freedom from interference spatial and temporal partitioning visualization. Real-world application ## ESC (Electronic Stability Control) case study The full FSC method is applied step by step to an Electronic Stability Control system, from system architecture and timing budgets to operating modes and a complete functional safety requirement set. - ESC system block diagram - sensors, main ECU, actuators, and warning channels - Timing model with ESC example values against a 200 ms FTTI budget - Operating modes state machine - initialization, normal, degraded, emergency, off - Safe state selection and degradation strategy with driver warning escalation - Complete FSR set derived from ESC safety goals with full traceability ESC timing example Fault detection and reaction completed within the 200 ms FTTI - with margin to spare Unlock in course Built for ## Who this guide is for - Engineers writing their first functional safety concept from HARA outputs - System engineers who must define safe states, warnings, and degradation strategies - Safety managers reviewing FSR quality and traceability before an assessment - Newcomers who want one complete, free ISO 26262 course before choosing a plan ## Frequently Asked Questions Common questions about Functional Safety Concept The fault tolerant time interval (FTTI) is the time span in which a fault can be present before a hazardous event becomes probable. The FSC has to guarantee that fault detection (FDTI) and fault reaction (FRTI) complete within the FTTI, with margin. The course teaches the full timing model - FTTI, FDTI, FRTI, FHTI, and EOTTI - with an interactive animated timeline that uses ESC example values, so you learn to build and check a timing budget rather than just memorize the acronyms. A safe state is an operating mode of the item without an unreasonable level of risk - for example, a function switched off with the driver warned, a degraded mode with reduced performance, or continued operation under redundancy. The FSC must define the safe state for every safety goal, how it is reached, and how long the system may take to get there. The course covers static and dynamic safe states with a dedicated interactive flow diagram, an operating modes state machine, and a warning and degradation strategy chapter. Yes. Functional safety concept is the concept included in the free plan: a free account unlocks all 13 chapters, the 9 interactive diagrams, the ESC case study, and 2 hours of scroll-synchronized video. It is a complete course, not a teaser, and it is the best way to evaluate how the platform teaches before upgrading. The Pro and Expert plans unlock the rest of the concept library. ## Start the course today A free account unlocks one full concept guide, 3 work product templates, 1 guided process, the Markov simulator, and 5 practice exams per month - plus 2 hours of course videos for registered users. The Pro and Expert plans unlock more of the 78-guide library. No credit card required. [Start learning](https://iso26262.academy/register?plan=free&from=%2Fconcepts%2Ffunctional-safety-concept&utm_source=website&utm_medium=cta&utm_campaign=features_concepts) [View Pricing Plans](https://iso26262.academy/pricing)