Functional safety certification: Risk assessment → rating → design evaluation + product testing (Source: SGS): Dual-track: ISO 13849 PL + IEC 61508 SIL (Source: Atos); Mechanical: ISO 13849-1 main framework (Source: arXiv) — Core: Category + DC + MTTFd to determine PL (Source: European Quality).
I. Standards System
ISO 13849: Mechanical SRP/CS PL a-e (Source: European); IEC 61508: Electrical and Electronic Systems SIL 1-4 (Source: Industrial Control Network); IEC 62061: Electrical and Electronic Systems SIL CL (Source: TÜV SÜD); Product Standards: Priority given to products with existing standards (Source: ifm); 13849-2: Validation Standards (Source: ISO) — System: 13849/61508/62061 (selected by technology).
II. Risk Assessment
Identification: Identify all potential risks (Source: ifm); Risk Map: Risk map assessment and classification (Source: ifm); Operating Conditions: Consider different operating modes (Source: ifm); Consequences: Consequence severity + exposure frequency (Source: Industrial Control Network); Objectives: Determine the required safety level (Source: Atos) — Assessment: Identification + Risk Map (Determine target level).
III. PL Levels
Definition: PL a-e discrete levels (Source: European); Elements: Category Structure + DC + MTTFd (Source: European); Category: B/1/2/3/4 structural categories (Source: Kirimas); DC: Diagnostic coverage (Source: Industrial Control Network); PL d: Common Cat.3 PL d (Source: Siemens) — PL: Structure + DC + Lifespan (three-element rating).
IV. SIL Levels
Definition: IEC 61508 Safety Integrity Levels (Source: JICS.com); Levels Four: SIL1-SIL4 progressively more stringent (Source: JICS.com); Quantification: Probability of hazardous failure per hour (Source: JICS.com); SIL2: 0.01% to 0.1% (Source: JICS.com); SIL3: 0.01% to 0.01% (Source: JICS.com) — SIL: Probability of Failure (Quantified Classification).
V. Certification Mode
Design Assessment: Design assessment + product testing (Source: SGS); Rules: PC-IND-SP-027 certification rules (Source: SGS); Verification: ISO 13849-2 analysis + testing verification (Source: Kirimas); Check: Whether the system is designed according to requirements (Source: Kirimas); Confirmation: Actual risk reduction meets the standards (Source: Kirimas) — Mode: Design + Testing (SGS certification rules).
VI. Life Cycle
Full Life Cycle: Meets SIL throughout the entire life cycle (Source: TÜV NORD); Early Stage: Early verification reduces costs (Source: TÜV NORD); Architecture: Correct product safety architecture (Source: TÜV NORD); Software: Embedded software requirements (Source: ISO); Documentation: Functional Safety Manual (FSM) (Source: JNC.com) — Lifecycle: Design → Verification → Maintenance (Full Life Cycle).
VII. Procurement Recommendations
1. **Select Standards** (13849/61508); 2. **Conduct Assessments** (Risk Map); 3. **Assess Levels** (PL/SIL); 4. **Go Through Certification** (Design + Testing);
5. **Preserve Evidence** (FSM + Verification) — Functional Safety: Standards + Assessment + Certification (Three-Line Closed Loop).
