Achieving reliable safety functions with high integrity
The use of instrumented systems in safety applications is increasing. The IEC 61508 standard is widely used by industries – such as oil and gas, process, transport and aviation – which need highly reliable safety systems. We have incorporated IEC 61511 in our procedures and our project execution model (PEM) to achieve full compliance with functional safety principles as specifi ed in IEC standards.
In order to determine the behaviour of an instrumented safety system, the design of its hardware and software needs to be fully assessed. IEC 61508 is the international standard for electrical, electronic and programmable electronic safetyrelated systems. It sets out requirements for ensuring that systems are designed, implemented, operated and maintained to provide the required safety integrity level (SIL). Four SILs are defined in accordance with the risks involved in the system application, with SIL 4 being used for the highest risks.
Guideline 070 from the Norwegian Oil Industry Association (OLF) is relevant to the NCS and referenced in the PSA regulations. Our procedures and PEM comply with OLF GL 070.
We can provide assistance with all aspects of IEC 61508, including:
- Developing project specific methodology to incorporate IEC 61508/61511 in a project scope of work
- Developing SIL requirements based on risk assessments
- Developing safety requirement specifications (SRS documents)
- Participating in the design process for safety systems to meet integrity requirements and the SIL
- Calculating the probability of failure on demand (PFD) to verify the SIL
- Conducting a functional safety assessment, third-party verification implementing and following-up in the operational phase