风险管理法则-Principles_of_Risk_Management
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Functional safety
Why does companies manage risk ?
Companies have a legal, moral and financial obligation to limit risk posed by their operation. Understanding the way this is expressed in a company helps to develop safety policy consistent with the way that company already works.
Increasing risk
Partial risk covered by External Risk Reduction Facilities
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Risk reduction achieved by all protective systems & External Risk Reduction Facilities
Risk Definition Measuring Risk Risk Tolerance Risk Reduction Safety Lifecycle and Risk Hazard Analysis Consequence and Likelihood
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Functional safety
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Functional safety
Measure Risk and Benefits
Both risk and benefits must be measured to intelligently determine what to do in virtually any situation Risk measurement must address both consequence and likelihood The consequence usually involve several forms of harm
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Functional safety
“External risk reduction facility”
External risk reduction facility are those measures to reduce or mitigate the risks which are separate and distinct from, and do not use, E/E/PE safety-related systems or other technology safety-related systems Example A drain system, a fire wall and a bund are all external risk reduction facilities
What is the nature of the risk ?
Fatality / Injury Permanent/Temporary Damage Financial Loss
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Functional safety
Individual Risk
Individual Risk:
Functional safety
What is Risk ?
Risk is a measure of the likelihood and consequence of an unwanted happening.
How often can it happened and what will be the effect (consequence) if it does ?
Prevention Concepts Taking action prior to the hazardous event taking place Mitigation concept Taking action after the hazardous event has taken place
What is Risk ?
What can happen ? Consequence * Likelihood (frequency) (10 people dead) * (every 200 years)
Calculated Process Risk
Process Design Other Risk Reduction, Such as Alarming, and Exception Procedures
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Functional safety
Levels of Risk and ALARP
Risk cannot be justified except in extraordinary circumstances Tolerable only if risk reduction is impracticable or if its cost is grossly disproportionate to the improvement gained
Low risk bound or tolerable region : 1*10-5 per year (1 / 100 000) High risk bound of tolerable region : 1*10-3 per year (1 / 1 000) The ALARP region (As Low As Reasonably Practicable) typically falls in between these bounds
Functional safety Engineering - Principles of Risk Management
Extended Automation System 800xA
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Functional safety
Principle of Risk Management
Functional safety
“Other technology safety-related system”
Other technology safety-related systems are safety related systems based on a technology other than electrical/electronic/programmable electronic Example A relief valve is another technology safety-related system
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Functional safety
Expression of Consequence
Measure the risk depend on two factors:
Who is being exposed to risk ?
Individuals Society Environment
Harm is effectively defined as the loss of benefits and thus brings benefits directly into the equation
All significant forms for harm must be considered to properly measure risk
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Functional safety
Basis for Risk Tolerance
Risky activities are tolerated because they provide benefits
Understanding both the risk and the benefits is critical to understanding what kind of risk can be tolerated in trade for what kind of benefits. There is no such thing as zero risk in the real world.
Mechanical equipment like reliefe valve, non return valve.
Fire pumps, foam systems, water curtains, deluge systems, ventilation emergency equipment and procedures
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Functional safety
Key terms and concepts “Risk”
Combination of the probability of occurrence of Reduce risk by: harm and the severity of that harm
Risk
Safety Instrumented System
Tolerable Level of Risk
(Defined by user per application)
Risk Reduction is the Highest Priority
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How often can it happened and what is the effect if it does ?
Build the lowest cost plant, keep operating budget as small as possible
