Functional Safety Studies / SIL

Arriscar provides a comprehensive approach to managing process risk specialising in functional safety in accordance with IEC 61508 and IEC 61511 principles.

There are three key steps in Safety Integrity Level (SIL) Assessment:

1. SIL Classification (or allocation) – Identification of the Safety Instrumented Functions (SIFs) and determination of their required level of reliability using a risk-based assessment method (e.g. risk graph and / or layers of protection analysis).
2. SIL Verification – The overall objective of the Safety Integrity Level (SIL) verification is to provide a detailed evaluation of the probability of failure on demand (PFD) of the Safety Instrumented Functions (SIFs) and determine if the SIL levels allocated to these functions in the SIL allocation study have been Depending on the architecture of the SIF either simple spreadsheet calculation or a more detailed Fault Tree Analysis can be used to undertake the evaluation of the PFD.
3. Safety Requirement Specification (SRS) and Life-Cycle Report – Documenting the requirements for each SIF in accordance with standards IEC 61508 / 61511.