The application of inherent safety to functional safety

Abstract

Functional safety has experienced evolution over the years aimed at further risk reduction in society. Changes have taken place in the form of the creation of new domain-specific standards such as ISO 26262 (automotive), EN 50129 (railway), ISO 13489 (machinery), etc. from the parent IEC 61508 standard. Besides, these standards also undergo periodic revisions to keep abreast of innovations in technology. As the technological space expands and increases in complexity, it needs more than procedural, passive and active risk reduction strategies to achieve optimal risk reduction due to potential deficiencies with the use of instruction manuals and physical safety barriers. Inherently safer design (ISD) is expected to bring about a consolidated and cost-effective risk reduction since it does not require the installation of degradable add-on features and can be applied across the product development life cycle. Hence, this paper aims to apply ISD to the functional safety aspect of safety system development according to IEC 61508. The paper focuses on hardware design and does not cover all aspects of active safety system design. The main objective is to investigate how ISD can reduce risk by reducing random and systematic failures. The paper builds on the review of literature and standards.

Keywords:

• Inherent safety
• functional safety
• IEC 61508

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Peter Okoh

Peter Okoh holds a PhD in Reliability, Availability, Maintainability and Safety (RAMS). He studied at the Department of Mechanical and Industrial Engineering, at Norwegian University of Science and Technology, Trondheim, Norway.