ISO 12100 · ISO 13849-1 · IEC 62061 · IEC 61508 · IEC 61511
Risk assessment and safety function design standards. Phase 3 Complete
PL vs SIL — Which Path?
The choice between Performance Level (PL) and Safety Integrity Level (SIL) depends on application domain:
| Domain | Approach | Standard | Foundation |
|---|---|---|---|
| Industrial machinery | PL (most common) | ISO 13849-1 | ISO 12100 |
| Industrial machinery (alternative) | Machinery SIL | IEC 62061 | IEC 61508 |
| Process industry | SIL | IEC 61511 | IEC 61508 |
| Generic E/E/PE safety | SIL | IEC 61508 | (foundational) |
ISO 13849-1 and IEC 62061 can be used together for complex machinery — ISO 13849-1 for mechanical/pneumatic elements, IEC 62061 for electrical/electronic safety functions.
Standards in This Family
ISO 12100 — Risk Assessment Foundation
Status: Complete
Foundation standard for all machinery safety. Required as the first step for CE marking. Provides a systematic process for risk assessment and risk reduction.
- Hazard identification
- Risk estimation and evaluation
- Risk reduction strategy (inherently safe design → safeguarding → information for use)
ISO 13849-1 — Performance Level (PL)
Status: Complete
Safety-related parts of control systems. The PL approach uses architectural categories (B, 1–4) and diagnostic coverage to determine the achievable Performance Level (PLa–PLe).
- Most common approach for industrial machinery
- Uses simplified reliability data (MTTFd, DC, CCF)
- Validated by ISO 13849-2 (validation methods)
IEC 62061 — Machinery SIL
Status: Complete
Functional safety for safety-related electrical control systems on machinery. Uses SIL (1–3) instead of PL. More aligned with IEC 61508 methodology but scoped to machinery.
- Can be used instead of or alongside ISO 13849-1
- More flexible for complex safety functions
- Required when SIL > 2 not achievable with ISO 13849-1 approach
IEC 61508 — Generic Functional Safety
Status: Complete
The foundation standard for all functional safety. IEC 62061 and IEC 61511 both derive from IEC 61508. Multi-part standard covering E/E/PE safety-related systems across all industries.
- Parts 1–7 cover the full safety lifecycle
- Part 3 covers safety-related software
- Rarely applied directly; usually via IEC 62061 or IEC 61511
IEC 61511 — Process Industry SIS
Status: Complete
Application standard for safety instrumented systems (SIS) in the process industry. Covers the SIS lifecycle from concept through decommissioning.
- Applies to oil and gas, chemicals, power generation, and similar process industries
- SIF (Safety Instrumented Function) design and allocation
- Proof test interval and PFDavg calculation
- Process SIS lifecycle, SIL determination, SIS design, and operation or maintenance pages are present in the local corpus
Standards Hierarchy Diagram
graph TD
ISO12100[ISO 12100
Risk Assessment] --> ISO13849[ISO 13849-1
PL approach]
ISO12100 --> IEC62061[IEC 62061
Machinery SIL]
ISO13849 --> IEC60204[IEC 60204-1
Implementation]
IEC62061 --> IEC61508[IEC 61508
Foundation]
IEC61511[IEC 61511
Process SIS] --> IEC61508
IEC61131[IEC 61131-3
PLC Software] --> IEC62061
IEC61131 --> IEC61508
This site is a personal-use paraphrase and navigation reference for industrial automation standards. It is not a substitute for authoritative standards documents, professional engineering judgment, or legal review. All content is sourced from a local RAG corpus and has not been independently verified against current published editions.
Items marked TO VERIFY have limited or unconfirmed local coverage. Items marked NOT IN CORPUS are not covered in the local repository. Do not rely on this site for compliance determinations, safety-critical design decisions, or legal interpretation.