IEC 62508 ED2

Guidance on human aspects of dependability

Scope

IEC 62508 : 2025 provides guidance on current knowledge and practice concerning dependability in an operational environment, in terms of the humans, teams and organizations involved in conducting the work. It is part of a suite of IEC standards that are intended to address the dependability of both the technical and human elements of equipment and organizations.

This document describes the human elements of a typical operational system, and the importance of those elements to overall dependability. It also describes the means of assessing how well these elements are functioning, and general concepts on how the reliability of humans can be improved. These elements typically include the individual workers, the groups or teams into which they are organized, the interfaces between humans and technical systems, and the overall organization.
The following guidance is applicable to any industry that depends on human-systems interactions involving the technology, software, or systems of work required to support the production and safety objectives of an organization. This document primarily addresses complex technical systems, but some parts are also applicable to the manufacturing of industrial and consumer products. Principles for design of the human-machine interface (usability) are described, and further information can be found in the technical literature and in relevant product standards. Although this document does not specifically cover worker health or safety, the application of this document can raise related issues, particularly in process safety, which is closely associated with system reliability.

This second edition cancels and replaces the first edition published in 2010. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) The emphasis on user-centred design in the previous edition was reduced in favour of a greater emphasis on human dependability in an existing operational environment.
b) The emphasis on human error and error-rate determination methods was reduced in favour of a greater emphasis on means of providing organizational support for the workforce in their execution of required tasks.
c) Where appropriate, discussions of human factors in an operational environment were aligned with current theory, terminology and practice.