The Common Language for Engineering
The ISO/IEC 81346 Standard Series is an international standard that provides you with the core rules for naming, structuring, and documenting objects and technical systems. Why? Because a clear reference model made by system structures helps you design, build, operate, and maintain even the most complex projects.
Collaborate Across Disciplines
As your technical systems grow in complexity, the risk of miscommunication, design inconsistencies, and costly errors increases. If you're an engineer working with processes, electrical systems, or mechanical design, you need a shared structure and terminology to ensure effective communication. When everyone uses the same system terms and can refer to the same systems—down to individual components—you build a shared understanding and stay aligned.
One Common Reference Model
ISO/IEC 81346 addresses this by offering you a shared architecture that allows cross-disciplinary teams to collaborate effectively—without forcing anyone out of their siloes. Each discipline can maintain its focus while still working within a common reference model that connects the entire system landscape. This makes it easier for you to see how everything fits together, where responsibilities lie, and how changes in one area might affect others.
Your organization gains a stable foundation that supports traceability, reuse, and efficient maintenance across the asset lifecycle. With ready-to-use classification tables and industry specific building blocks, the standard helps you reduce errors, accelerate development, and ensure that your data and knowledge remain scalable, reusable—and most importantly—retained within your organization, even as teams change or grow.
The fundamentals
81346-1: Basic Rules
IEC 81346-1 defines the basic rules and principles used across the entire 81346 standard series. It provides a standardized method for organizing system decompositions, and identifying technical systems across engineering disciplines.
The standard defines aspects, which are different viewpoints used to describe systems. These include the functional aspect (what something does), the product aspect (what something is), the location aspect (where something is), and the type aspect (what kind or class of object it is).
It also explains how to structure these systems, meaning how to organize technical systems into smaller, more manageable parts in a logical and hierarchical way.
81346-2: Classification
IEC 81346-2 is a standard that provides an overall classification scheme consisting of letter codes, definitions, preferred term and examples. The framework is built on system classification methodologies in accordance with ISO 704 and ISO 22275. The standard include classification tables for all component systems, as well as construction complexes, construction entities and spaces. The classifications are realized by letter codes that help you instantly recognize what kind of system you’re working with to create a shared technical language.
You classify your systems using up to three letter codes. For example, a one-letter code (main system) - “Wind turbine” - A1, a two-letter code (technical system) - “Drive chain” - JF1, and a three-letter code (component system) - “High speed axle” - WQA1.
When modeling systems in certain industries, a need for industry specific classification libraries arose and is still expanding. The development is still continuing, and several libraries have already been published.
81346-10: Power Supply Systems
ISO 81346-10, also known as RDS-PS, is a standard developed for the energy power supply sector.
It provides industry specific classification libraries that can be applied within the PtX, nuclear, oil, energy storage, wind, hydro, natural gas, solar, and coal industries to structure industrial systems.
Industry specific standards
81346-12: Construction Works
ISO 81346-12, also known as RDS-CW, is a standard developed for the construction sector but can also be applied in other sectors.
It provides industry specific classification libraries that can be applied within the construction, urban areas, utility, and HVAC industries.
81346-14: Manufacturing Systems
IEC 81346-14, also known as RDS-MS, is a standard developed for all industries within manufacturing systems and processing sector.
It provides industry specific classification libraries that can be applied, e.g., within the consumer goods, machine building, industrial equipment, food & beverage, pharmaceuticals, packaging, and mining industries.
Series In Development
81346-8: Properties
Status: Currently in the preparatory (20.00) stage, expected to be published in early 2027.
Overview: The ISO/IEC 81346-8 provides a scheme for identifying characteristics of objects and systems, ensuring clear identification of properties in technical documentation. The standard is designed to support the design phase of systems and make properties an important relation to object occurrences.
81346-20: Vehicle Systems
Status: Currently in the Preparatory (20.00) stage, expected to be published in early 2027.
Overview: The ISO/IEC 81346-20, or RDS-VE, is a new standard that addresses systems within the broader term of "vehicles." The standard covers the design, planning, processing, and maintenance of aircrafts, vessels, motor vehicles, trains, and any other means of transportation vehicle.
81346-50: Processes
Status: Currently in the Committee Draft (30.60) stage, expected to be published in 2026.
Overview: The ISO/IEC 81346-50 is the first of its kind, providing a method for structuring and classifying processes and activities, not systems. This new framework creates new modeling techniques and standard approaches to create reference designations for things you do, both in labeling IT systems and designating technical documents.
81346 in context of other standards
IEC 81355
The foundation for a good management of documents is a well organized reference designation system.
IEC 61355‑1 provides rules for the classification and designation of documents used across the life cycle of technical systems.
The 2024 cross‑standard ISO/IEC 81355 succeeds IEC 61355 and shifts from traditional “document classification” to more modern “information classification,” aligning documentation with digital engineering practices and improving consistency across disciplines.
Where 81346 structures systems through aspects and reference designations, 81355 structures the information and documentation surrounding those systems, making the two standards complementary.
ISO 15926
When reference designations are in place there needs to be common protocols in order to exchange information
ISO 15926 is an international standard for data integration, sharing and handover across computer systems, particularly in industries like oil & gas, process plants, shipbuilding and CAD/PDM platforms.
Its goal is to unify life‑cycle information so that all engineering data can be exchanged with shared meaning using a common data model and reference data library.
Where 81346 structures technical systems and their reference designations, ISO 15926 structures the data that describes those systems. Using them together enables both a consistent system architecture (81346) and a consistent semantic data layer (15926).
ISO/IEC/IEEE 15288
Reference designations are built up around systems thinking and a natural extension of this perspective is to apply the standard across the life cycle of an object.
ISO/IEC/IEEE 15288 defines a common framework of processes for the entire system life cycle, from conception and development to operation and retirement, providing a standard vocabulary and process model for systems engineering.
It outlines agreement processes, organizational processes, technical management processes, and technical processes used by acquirers and suppliers across complex projects.
Where 81346 provides a structuring method for organizing systems and components, 15288 provides the process framework organizations follow to develop, manage, and govern those systems