EN ISO 13849-2:2012 — what is new/relevant
Machine safety
This standard describes how to demonstrate that the safety functions in your control system actually work as designed. It complements EN ISO 13849-1 (design & assessment) with a structured validation through analysis and testing.
EN ISO 13849 deals with the safety-related parts of control systems (SRP/CS). Part 1 – Design and assessment (EN ISO 13849-1:2023) covers the design and assessment of safety functions; Part 2 – Validation (EN ISO 13849-2:2012) covers validating (through analysis and testing) that the design has been implemented correctly.
Harmonisation: EN ISO 13849-2:2012 is harmonised under the Machinery Directive, so applying it gives a presumption of conformity. In practice, always use the latest state of the art (e.g. 13849-1:2023 for design) and secure validation in accordance with Part 2.
Context and relationship with older standards
EN ISO 13849 replaced the former EN 954. Since then, EN ISO 13849 has been the reference for Performance Level (PL)-based safety controls.
What does EN ISO 13849-2:2012 require?
Purpose: to demonstrate (through analysis and testing) that the safety functions, the chosen category (Cat. B, 1, 2, 3, 4) and the achieved performance level (PL a–e) correspond to the design according to EN ISO 13849-1.
Among other things, the standard specifies the independence of the validator (the person validating may not have created the design), the validation steps, documentation and test methods.
Key points of validation (selection):
- Demonstrating reliability (Mean Time To Dangerous failure, MTTFd) for safety-relevant components.
- Determining and proving diagnostic coverage (DC).
Addressing common cause failure (CCF) with appropriate measures. - Checking whether the intended category and PL are actually achieved (depending on architecture, DC and MTTFd).
Annexes with tools: the standard contains annexes with examples (electrical, hydraulic) and an example validation for an assembly machine (Annex E). Useful as a guide for validation matrices, test cases and fault diagnosis.
What changed with EN ISO 13849-1:2023?
The 2023 edition of Part 1 positions validation more explicitly as part of the design process (final phase). Part 2 remains the normative framework for planning, executing and recording validation.
