Safety is the freedom from unacceptable risk of physical injury or damage to the health of people, either directly or as a result of damage to property or the environment.
Functional safety is the part of the overall safety of a system or piece of equipment that depends on the system or equipment operating correctly in response to inputs, regardless of source or external effects.
Functional safety scope is intrinsically end-to-end in that it treats the part or subsystem as an integral part of the whole. That is, the safety instrumented system includes all components and subsystems necessary to carry out the safety instrumented function from sensors to final elements.
The adoption by British Standards of functional safety standards IEC 61508 and IEC 61511 provide guidelines to duty holders on the application and management of Programmable Electronic Systems (PES), such as PLCs, in safety critical applications, from process concept to de- commissioning. All CENELEC member countries adopted IEC61508 in August 2002, all equivalent national standards were withdrawn in 2004.
Common to each of these directives and standards is the need for duty holders to demonstrate that risk has been reduced to a level which is "As Low As Reasonably Practical" (ALARP).
When to consider functional safety?
Whenever a duty holder considers upgrading or implementing a new process, which entails safety critical aspects being managed and controlled by an Electrical, Electronic or Programmable System (E/E/PS) system, due consideration must be given to IEC 61508 or its derivatives.
We offer a comprehensive range of functional safety services to meet the requirements of IEC 61508 and IEC 61511 projects. These range from support during HAZIDs and HAZOPs to the generation of Safety Requirements Specifications, SIL calculations, safety project planning and audits. All carried out under the supervision and management of our TÜV certified, functional safety professional engineers.
Our Functional Safety Management System (FSMS) has been independently validated. So you can be assured that we have the correct systems in place to manage projects safely and professionally.
For over a decade Charter Tech has been a member of the 61508 Association. It’s an association of companies and certification bodies with an interest in gaining the full benefits of successfully implementing IEC 61508 and derivative standards such as IEC 61511.
The members include manufacturers, integrators, certification bodies and observer companies such as the Health and Safety Executive (HSE).
The 61508 Association is a trusted and authoritative body, involved in reviewing and commenting on standard amendments and enhancements before they are implemented.
For further details on the 61508 Association please click here to visit the website.
Summary of functional safety services:
Safety Requirement Specification generation
Functional Safety Assessments
SIS design and engineering
Application program specification