EN 5012N

Overview of the EN 5012n series of standards

Systems for the control and safety of railway traffic have to meet especially high quality requirements. The requirements for telecommunications technology, signalling systems and information processing systems are defined by the EN 5012n European series of standards.

The corresponding series of DIN standards comprises the following individual standards:

  • DIN EN 50126
  • DIN EN 50128
  • DIN EN 50129

EN 50126 includes requirements for the specification and verification of reliability, availability, maintainability and safety. EN 50128 comprises requirements for safety-related software, and EN 50129 defines requirements for safety-related electronic systems.

Other information

Basic standard

The EN 5012n series of standards is published by CENELEC (Comité Européen de Normalisation Electrotechnique) and is based on the international IEC 61508-n standard. The equivalent German series of standards is DIN EN 61508-n:2011-02 of February 2011.

The IEC 61508 basic standard comprises requirements for safety-related electrical/electronic/programmable systems and is aimed at achieving defined safety objectives. It thus intends to reduce possible safety risks to a tolerable level.


The fundamental questions arising in respect of standards application are Why? and How? Even though the EN 5012n series of standards formulates appropriate requirements, it does not represent a "recipe" for developing embedded systems for safety-related railway applications. It does, however, form the basis both for a safety-focussed development process and for corresponding quality management throughout the life cycle of an embedded system.


Safety standards are exceptional among standards in general because compliance with the former is mandatory within their particular area of application. The specifications/requirements of the EN 5012n series of standards in the railway industry are part of what is referred to as "state of the art" technology. Compliance with the requirements of those standards is a fundamental prerequisite for the official approval of the systems concerned.

As mentioned before, the fundamental purpose of the standards is to minimise risks in the application of the system in question.

Beyond that, the aspect of risk minimisation can be extended to other areas such as scope of contract, acceptance criteria and approval criteria.

The highest risk ultimately lies in the failure of a system implemented and/or operated without observing the standards. In such a case the risk lies not only in potential loss or damage but also in a presumable organisational failure.

The series of standards can/should form the basis for standardising processes and procedures. This applies both to internal project handling and to the client/contractor relationship; it should include all parties involved in the project and in the approval procedure.


The standardisation of processes and procedures as defined by the series of standards should be implemented across the entire life cycle, i.e. it should not end with the approval procedure. In the development process, the main focus should be on a systematic and methodical procedure. Compliance with the requirements of the series of standards series should be integrated into the project. Standardisable, generic elements and/or project-specific elements should be developed with the overall life cycle of a system and/or future projects in view. A retrospective documentation of a project based on the series of standards is not what the standards are aimed at.

Where are we heading? prEN 50126-n

The EN 5012n series of standards is being fundamentally revised; thus, it is currently available as a "pre-release". You have a clear view of the developments of the coming years. You want to know what to expect in terms of project work. You want to act and broaden your scope of action. Your aim is to prepare necessary changes with pinpoint accuracy.

What OntoTec offers to help you

  • Content analysis
  • Definition of alternative courses of action
  • Target-focused implementation