ISA TR84.00.02
Safety Integrity Level (SIL) Verification of Safety Instrumented Functions
Organization:
ISA - International Society of Automation
Year: 2015
Abstract: ISA-TR84.00.02-2015 is informative and does not contain any mandatory clauses. ISA-TR84.00.02 is intended for use by those with a thorough understanding of ISA-84.00.01-2004 Part 1. This document assumes that a SIS is required. It does not provide guidance on the hazard and risk assessment used to identify the need for a SIS. The user is referred to ISA-84.00.01-2004 Part 3, and CCPS’s Hazard Evaluation Procedures and Layers of Protection Analysis:Simplified Risk Assessment for guidance on assigning the SIL.
Prior to proceeding with use of ISA-TR84.00.02-2015, the hazards and risk assessment and the allocation of safety functions to protection layers should be completed and the following information provided:
At least one SIF is required
The functional requirements of the SIF
The integrity requirements of the SIF
ISA-TR84.00.02-2015 provides guidance on different issues that impact SIL verification:
Assessing random and systematic failures, classifying failure modes, and estimating the failure rates for individual devices of an SIF;
Assessing the impact of diagnostic and mechanical integrity choices on the performance of the SIF and its devices;
Assessing and estimating the potential for common cause and common mode failures; and Verifying that the SIF achieves a specified SIL and spurious trip rate.
ISA-TR84.00.02 provides guidance on techniques for evaluating the following:
Average probability of failure on demand for low demand mode Spurious trip rate
There are four topics that are being held until the next revision of ISA-TR84.00.02. Until then, the reader should refer to ISO 12489 for appropriate methodologies.
Prior to proceeding with use of ISA-TR84.00.02-2015, the hazards and risk assessment and the allocation of safety functions to protection layers should be completed and the following information provided:
At least one SIF is required
The functional requirements of the SIF
The integrity requirements of the SIF
ISA-TR84.00.02-2015 provides guidance on different issues that impact SIL verification:
Assessing random and systematic failures, classifying failure modes, and estimating the failure rates for individual devices of an SIF;
Assessing the impact of diagnostic and mechanical integrity choices on the performance of the SIF and its devices;
Assessing and estimating the potential for common cause and common mode failures; and Verifying that the SIF achieves a specified SIL and spurious trip rate.
ISA-TR84.00.02 provides guidance on techniques for evaluating the following:
Average probability of failure on demand for low demand mode Spurious trip rate
There are four topics that are being held until the next revision of ISA-TR84.00.02. Until then, the reader should refer to ISO 12489 for appropriate methodologies.
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Modeling of continuous and high demand mode systems -
Understanding proof test effectiveness and how this is addressed by design and mechanical integrity practices -
Understanding how to model common cause and systematic contribution to the failure of subsystems and systems and to the occurrence of the hazardous event -
Expanding the discussion of common cause and systematic error to address these issues across the entire lifecycle
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contributor author | ISA - International Society of Automation | |
date accessioned | 2017-09-04T17:10:51Z | |
date available | 2017-09-04T17:10:51Z | |
date copyright | 2015.09.08 | |
date issued | 2015 | |
identifier other | CABSMFAAAAAAAAAA.pdf | |
identifier uri | http://yse.yabesh.ir/std;query=autho47037D83081DAC4269728F1E273C9FCD/handle/yse/134435 | |
description abstract | ISA-TR84.00.02-2015 is informative and does not contain any mandatory clauses. ISA-TR84.00.02 is intended for use by those with a thorough understanding of ISA-84.00.01-2004 Part 1. This document assumes that a SIS is required. It does not provide guidance on the hazard and risk assessment used to identify the need for a SIS. The user is referred to ISA-84.00.01-2004 Part 3, and CCPS’s Hazard Evaluation Procedures and Layers of Protection Analysis:Simplified Risk Assessment for guidance on assigning the SIL. Prior to proceeding with use of ISA-TR84.00.02-2015, the hazards and risk assessment and the allocation of safety functions to protection layers should be completed and the following information provided: At least one SIF is required The functional requirements of the SIF The integrity requirements of the SIF ISA-TR84.00.02-2015 provides guidance on different issues that impact SIL verification: Assessing random and systematic failures, classifying failure modes, and estimating the failure rates for individual devices of an SIF; Assessing the impact of diagnostic and mechanical integrity choices on the performance of the SIF and its devices; Assessing and estimating the potential for common cause and common mode failures; and Verifying that the SIF achieves a specified SIL and spurious trip rate. ISA-TR84.00.02 provides guidance on techniques for evaluating the following: Average probability of failure on demand for low demand mode Spurious trip rate There are four topics that are being held until the next revision of ISA-TR84.00.02. Until then, the reader should refer to ISO 12489 for appropriate methodologies.
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language | English | |
title | ISA TR84.00.02 | num |
title | Safety Integrity Level (SIL) Verification of Safety Instrumented Functions | en |
type | standard | |
page | 136 | |
status | Active | |
tree | ISA - International Society of Automation:;2015 | |
contenttype | fulltext |