SIL Safety Lifecycle & Management 2

Question 1

During which phase of the IEC 61511 safety lifecycle is a Process Hazard Analysis (PHA) most appropriately conducted?

Accepted Answer

During the concept and hazard identification phase

Answer

The PHA is conducted during the early concept and hazard identification phase to identify hazards before design decisions are locked in.

Question 2

What document formally defines the functional and integrity requirements of each Safety Instrumented Function (SIF) before detailed design begins?

Accepted Answer

Safety Requirements Specification (SRS)

Answer

The Safety Requirements Specification (SRS) formally captures the functional and integrity requirements for each SIF prior to design.

Question 3

Which lifecycle phase immediately follows the Safety Requirements Specification in IEC 61511?

Accepted Answer

SIS design and engineering

Answer

After the SRS is established, the next lifecycle phase is the design and engineering of the Safety Instrumented System.

Question 4

In IEC 61511, what is the primary purpose of a Functional Safety Assessment (FSA)?

Accepted Answer

To verify that functional safety has been achieved or is on track to be achieved

Answer

The FSA provides an independent judgment of whether the safety lifecycle activities have been conducted correctly and functional safety is achieved.

Question 5

What is the minimum recommended number of independent Functional Safety Assessments during the IEC 61511 lifecycle for a high-risk application?

Accepted Answer

Multiple, at key lifecycle phases such as after SRS, after design, and after installation

Answer

IEC 61511 recommends FSAs at multiple key phases — including after SRS completion, after design, and after installation — to catch issues early.

(SIL) Safety Integrity Level Certified Practice Test