Definition:
Target Safety Integrity Level (Target SIL) is the required SIL determined during the SIL allocation process. This is typically done via a LOPA or could be with a risk graph and a few others.
Target SIL is the required level of risk reduction (SIL 1, 2, 3, or 4) identified during analysis, before design or implementation of the SIF. The design and validation teams must then verify that the SIF, as built and configured, meets or exceeds that target.
Key Points:
- Guides design and verification efforts.
- Based on risk reduction needed to meet tolerable risk.
Example:
A HAZOP/LOPA determines a SIF requires a Target SIL of 2 to reduce explosion risk to achieve company (or regulatory) levels. The design team then creates a solution to meet or exceed SIL 2.
See also: SIL
Cited Source:
- IEC 61511-1:2016, Clause 9.2.