How to ensure compliance with functional safety standards

If you are looking for concise yet accurate answers to the key questions about compliance with functional safety standards for components, systems, and industrial plants, you are in the right place. Discover useful information for day-to-day operations, explored in depth and verified by our assessors, certified FS Engineers (TÜV Rheinland).

1. What documents are required to demonstrate compliance with IEC 61511?

To demonstrate compliance with IEC 61511 in an Oil & Gas, chemical, or energy plant, the following are required:

• Risk analysis, including the specification of the techniques used
• A detailed SRS (Safety Requirement Specification) for each safety function, and the Safety Manual for commissioning
• SIL calculations for hardware/software/firmware architectures and the related reliability calculations, such as PFDavg
• Verification and validation reports, including functional testing
• Maintenance plan
• Technical change documentation
• Internal or third-party audit reports

2. How should one prepare for a functional safety audit?

A functional safety audit verifies whether safety functions have been properly designed, implemented, and managed throughout the entire lifecycle of the device.
 
It is therefore essential to have appropriate documentation available, including:

• Work phases (from risk analysis to the implementation of changes)
• Roles and responsibilities, where a management system compliant with the standards has been established
• Functional tests and validation testing
• Maintenance plan

3. What functional safety certifications are recognized?

There are functional safety certifications both for personal competence and for product compliance.
 
The most widely recognized personnel certification is the TÜV Functional Safety Engineer/Expert, issued by TÜV Rheinland, which our specialists also hold in order to guarantee the highest level of competence in this field.
 
As for components intended for safety functions, they can be SIL certified by third-party bodies, including BYHON. Although IEC 61508 requires compliance rather than certification, certification provides an important boost to product reliability and, consequently, to market potential.

4. What is the difference between an accredited SIL certificate and a standard certificate?

A SIL certificate is accredited when the certification body issuing it has itself been assessed by a third party, specifically according to the ISO/IEC 17065 scheme, which is specific to products and processes, and with a scope that includes the IEC 61508 functional safety standard.
 
This does not mean that a non-accredited certificate is false, but rather that, due to the lack of a formal third-party assessment of the issuing body, in some contractual or regulatory cases a non-accredited certificate may not be sufficient. Read the full article.