Definition:
A Functional Safety Assessment (FSA) is an independent review process conducted to confirm that functional safety activities have been properly completed and that life-cycle objectives have been achieved. Most FSA activity is related to the design of the SIS. An FSA is distinct from an audit, which is more applicable during operations.
There are five stages of an FSA. Often companies will take each step and split it into two steps.
- Stage 1 – after H&RA is complete, protection layers identified, and SRS developed
- Stage 2 – after SIS is designed
- Stage 3 – after installation, pre-commissioning, and final validation of the SIS
- Stage 4 – after gaining experience in operating and maintenance
- Stage 5 – after modifications and prior to decommissioning
How it fits: For how a functional safety assessment differs from an audit, and where each sits in the IEC 61511 life-cycle, see Functional Safety Assessment (FSA) vs. Audit: What’s the Difference?.
Key Points:
- FSAs are required at multiple stages of the safety life-cycle (FSA 1 through FSA 5).
- Conducted by individuals independent of the original project team.
- FSA stage 3 roughly aligns with a Pre-Start-Up Safety Review (PSSR)
Example:
An FSA 3 ensures that all SIL verification, validation, and commissioning activities are complete before startup. In other words, to ensure the design meets the requirements of IEC 61511-1.
See Also: audits, verification, PSSR, CDOIF
Cited Source:
- IEC 61511-1:2016, Clause 5.2.6.
- Method Functional Safety – The 5 Functional Safety Assessment (FSA) Stages
- eFunctional Safety – article on Audit and FSA