ISO 13849: Combining Safety Functions — Series PL Alignment and the Annex K Lookup in Practice

Date
2027-02-01
Location
Online
Host
Zach L

About this event

A live 30-minute expert session on Combining Safety Functions — Series PL Alignment and the Annex K Lookup in Practice (ISO 13849 — Machinery Safety). What We'll Cover: What subsystem combination is and where overall-PL evaluation closes the quantitative verification stage The combination method step by step: sum PFHd values, apply the more-than-three-subsystems table, and check PL alignment How the calculation maps to Clause 6 and Annex K and the combined safety-function summary table produced Common mistakes: averaging PLs instead of taking the constraint, and forgetting the field device chain outside the safety PLC The end-to-end sensor-logic-actuator calculation evidence an auditor wants for every claimed overall PL Related topics: subsystem combination · overall pl · pfhd summation ·

Topics

Registration

View event page

About Functional Safety Foundations

This online session delivers expert-led instruction on the regulatory landscape and implementation approach for Functional Safety Foundations.

The cross-sector fundamentals underlying every functional safety standard: risk as severity × likelihood, the safety function concept, integrity levels, the safety lifecycle, and the split between random and systematic failures.

What it regulates

Shared vocabulary and reasoning: hazard → risk → risk reduction allocation → safety requirement → verified implementation → maintained integrity in operation.

Who must comply

Everyone entering the field — the conceptual base of the entire catalog.

Key requirements of Functional Safety Foundations

  • Hazard and risk fundamentals
  • Safety function anatomy: sensor-logic-actuator with defined safe state
  • Integrity ladders (SIL/PL/ASIL/DAL) as risk-reduction currencies
  • Random vs systematic failure treatment
  • Lifecycle and management of functional safety incl. competence

Key concepts: Functional Safety Foundations

Functional safety management
Planning, competence, documentation and assessment wrapped around technical work.
Risk reduction allocation
Distributing required risk reduction among mechanical design, safeguards, control functions and procedures.
Random vs systematic
Hardware wear-out/chance failures quantified statistically versus design/process errors controlled by rigor.
Safe state
The defined condition a function drives the equipment to on demand or fault.

Frequently asked questions: Functional Safety Foundations

Why can't testing alone prove safety?

Rare-event targets (like 1e-7/h) are unverifiable by test duration, and systematic errors evade random testing — hence the standards' dual machinery of quantified hardware analysis plus process rigor and independent assessment.

Standard information based on the published text of Functional Safety Foundations. Event content is provided by the host. For authoritative guidance, consult the official standard body.