Q&A on the phases of the functional safety lifecycle

If you are looking for concise yet accurate answers to the key questions about the functional safety of components, systems, and industrial plants, you are in the right place. Discover how to manage product responsibilities throughout its lifecycle, along with other useful insights for day-to-day operations, explored in depth and verified by our assessors, certified FS Engineers (TÜV Rheinland).

1. Who is responsible for SIL analysis in a project?

Typically, responsibility for functional safety lies with the person in charge of designing the electrical part of the devices, or with the R&D specialist, firmware or software managers, and all other roles involved in ensuring compliance of the safety management system according to the standards. Therefore, in industrial practice, SIL analysis is handled by a multidisciplinary team that must ensure the compliance of the safety system.
 
If you are looking for an independent third party to work alongside your internal team in achieving compliance objectives, contact us.

2. What is the difference between SIL Verification and SIL Validation?

Verification is the engineering calculation activity used to demonstrate that a safety function has been specifically designed to achieve the required SIL level.
 
Validation, on the other hand, is the subsequent phase used to demonstrate in the field that the function is activated as expected under real operating conditions.
 
Here you can find more information on validation according to functional safety standards applied to machinery.

3. How is SIL maintained over time?

It is maintained by following the requirements of the safety lifecycle for the phases of operation, maintenance, and repair, as well as modification and retrofit.
 
If you are looking for an independent third party to work alongside your internal team in achieving compliance objectives, contact us.

4. How is an independent verification of safety functions carried out?

Verification must be performed by individuals who are independent from the design team and have a high level of expertise in functional safety, in order to check the correctness of the technical specifications, the SIL level calculation, the system architecture, and compliance with the standards, and to identify any shortcomings before the device is commissioned.

5. How is the safety lifecycle documented?

The functional safety lifecycle can be documented by assessing the adequacy of the functional safety achieved by the analyzed equipment against the clauses established by functional safety standards, in preparation for the possible achievement of SIL certification.
The Functional Safety Assessment (FSA) is an appropriate tool for this purpose.