ISO 25119-1:2018

Overview

ISO 25119-1:2018 - "Tractors and machinery for agriculture and forestry - Safety-related parts of control systems - Part 1: General principles for design and development" - defines general principles for the design, development and lifecycle management of safety-related parts of control systems (SRP/CS) implemented as electrical, electronic or programmable electronic systems (E/E/PES) on tractors, agricultural and forestry machines, self-propelled ride‑on machines and certain mounted or trailed machines. The standard is a type-B1 (generic safety) standard and complements machine‑specific (type‑C) standards and ISO 12100 risk‑assessment guidance.

Key topics and technical requirements

• Scope and applicability: Applies to SRP/CS on agricultural, forestry and some municipal mobile equipment (e.g., street sweepers). Excludes aircraft, air‑cushion vehicles, lawn/garden equipment and non‑E/E/PES systems (hydraulic, mechanical, pneumatic).
• Safety lifecycle management: Requirements for planning and managing functional safety across design, verification, production, operation, maintenance and decommissioning (safety life cycle).
• Functional safety management: Quality management prerequisites, assignment of responsibilities, training, continuous improvement and documented work products (safety plans, test plans).
• Risk‑based approach & performance levels: Defines allocation of SRP/CS capability into five performance levels based on architecture (categories), diagnostic coverage, reliability (MTTFd), common‑cause failures and operating conditions. Note: ISO 25119‑1 sets characteristics and categories but does not mandate AgPL/performance levels for specific applications - type‑C standards or the manufacturer specify AgPL.
• Failure modes & architecture: Addresses systematic, random and common‑cause failures and how architecture and diagnostics affect achievable performance levels.
• Verification & assessment: Guidance for verification, validation and third‑party assessment activities and required documentation.
• Scope limits: Does not address hazards unless caused by E/E/PES malfunction (e.g., it excludes general electric shock, fire, corrosion hazards unless directly due to SRP/CS malfunction).

Practical applications

• Design and development of safety functions (e.g., emergency stop, interlocks, steer‑by‑wire) implemented with E/E/PES.
• Preparing safety plans, test plans, production/test procedures and traceability for SRP/CS.
• Verifying and validating functional safety claims and supporting conformity assessment for agricultural and forestry machinery.
• Integrating SRP/CS requirements into supplier contracts and manufacturing processes.

Who uses this standard

• Machine manufacturers (OEMs) of tractors, agricultural/forestry and municipal mobile machines
• Safety engineers and embedded systems designers working on E/E/PES
• Regulatory bodies, conformity assessors and market surveillance authorities
• Service providers, maintenance organizations and standardization bodies drafting type‑C standards

Related standards

• ISO 12100 (general machinery risk assessment and design principles)
• Type‑C machine‑specific standards (may specify AgPL/performance levels for specific machines)

Keywords: ISO 25119-1, SRP/CS, E/E/PES, safety-related parts of control systems, tractors safety, agricultural machinery functional safety, safety lifecycle, performance level.