The Risk Based Allocation of Safety Integrity Levels for Machinery Control Systems and the International Standard IEC 62061

Abstract

Abstract This paper outlines the draft international standard IEC 62061 – Safety of machinery – Functional safety – Electrical, electronic and programmable electronic control systems [1]; this is intended to be a machinery sector implementation of the basic safety publication IEC 61508 – Functional safety of electrical/electronic/ programmable electronic safety-related systems [2]. A fundamental concept of IEC 61508 is the definition of safety performance criteria for safety functions implemented by safety-related electrical, electronic and programmable electronic systems in terms of safety integrity levels (SILs). This paper, therefore, goes on to describe a methodology, currently under development, for the risk based selection of SILs that it is proposed should be incorporated into an informative annex of IEC 62061.