Safety Lifecycle & Management Flashcards
7 cards from real SIL practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Safety Lifecycle & Management flashcards as text
What is the primary distinction between a Safety Instrumented System (SIS) and a Basic Process Control System (BPCS)?
Answer: The SIS is a dedicated independent protective layer while BPCS maintains normal operations
The SIS is an independent protection layer designed to bring the process to a safe state, separate from the BPCS that handles normal control.
In the context of functional safety management, what is a 'Safety Case'?
Answer: A structured argument supported by evidence that a system is safe for its intended operation
A Safety Case is a documented argument with supporting evidence demonstrating that a system meets its safety requirements for a defined operational context.
What is 'beta factor' in the context of SIL calculations for redundant systems?
Answer: A measure of the fraction of failures that are due to common cause
The beta factor represents the proportion of failures in a redundant system that are caused by a common shared cause, reducing the benefit of redundancy.
Which IEC 61511 requirement addresses the need to assess the suitability of existing (prior use) equipment for use in a SIS?
Answer: Prior use justification
IEC 61511 allows equipment without third-party SIL certification if prior use evidence demonstrates adequate field performance in similar applications.
What does 'spurious trip rate' measure in a Safety Instrumented System?
Answer: How often the SIS activates when there is no actual process hazard
Spurious trip rate measures how often the SIS unnecessarily brings the process to a safe state, which can impact process availability and safety culture.
The IEC 61511 safety lifecycle starts with which foundational activity?
Answer: Hazard and risk assessment to identify and characterize process hazards
The IEC 61511 lifecycle begins with a Hazard and Risk Assessment to identify process hazards and determine the risk reduction needed.
In IEC 61511, what is meant by 'functional safety audit'?
Answer: A systematic examination to determine whether functional safety activities comply with planned arrangements
A functional safety audit is a systematic, independent examination verifying that the organization's processes and activities conform to planned functional safety requirements.