RISK MANAGEMENT SYSTEM | HAZARD IDENTIFICATION AND RISK SCREENING | RISK ANALYSIS AND EVALUATION | QUALITATIVE RISK ASSESSMENT | SEMI-QUANTITATIVE RISK ASSESSMENT | QUANTIFIED RISK ASSESSMENT
Risk Management
RISK MANAGEMENT
SYSTEM | HAZARD IDENTIFICATION AND RISK SCREENING | RISK ANALYSIS AND
EVALUATION | QUALITATIVE RISK ASSESSMENT | SEMI-QUANTITATIVE RISK ASSESSMENT | QUANTIFIED
RISK ASSESSMENT
RISK MANAGEMENT
SYSTEM
Risk management can only be achieved through the management
of known and potential hazards and risks.
This requires the definition of a Risk Assessment and Management
System. The element of Risk Management requires that companies.
The Companies and affiliates have programs and procedures i.e.
risk assessment & management systems which must:
·
Identify hazardous activities, the potential
hazardous event, and their consequences
·
Assess and prioritize risks in a cost-effective
manner
·
Ensure that HSE reviews are carried out for the design
and operation of facilities
·
Ensure that acquisitions and asset disposal are
evaluated for HSE risks
·
Ensure that HSE hazards from equipment and
facility decommissioning are managed.
The HSE risk management process is an integral part of
management, and decision-making and is integrated into the structure,
operations, and processes of the organization. Risk management process in ISO 31000:2018
Risk Management – Guidelines.
HAZARD IDENTIFICATION
AND RISK SCREENING
Hazards that may arise throughout the life cycle of
companies and the causes that could lead to potentially hazardous events
resulting in undesirable consequences should be systematically identified.
Hazard Identification is the first step in the risk
assessment process. This can be done using structured techniques such as HAZID,
Inherently Safer Design, Review, HAZOP, SIMOPS, JSA, etc., or for existing
facilities can be through periodic review, audits, inspections, near-miss
reporting, incident learning, etc. HSE audit, HSE inspection, etc. may also
provide input to hazard identification.
Hazards are identified, for project phases, and they are
screened into Major Accident Hazards which typically represent High and
High-Medium Risks and Non-Major Accident Hazards which usually represent Medium
and Low-Risk hazards. For the operations phase, based on the risk mapping the
hazards are screened into High, High-Medium, Medium, and Low categories.
RISK ANALYSIS AND
EVALUATION
The process of carrying out a risk assessment will result in
an understanding of the level and significance of HSE risks that leads to
Informed Decisions related to the implementation of appropriate risk control and
risk reduction measures. The risk assessment consists of two parts, Risk
Analysis, and Risk Evaluation.
Risk analysis involves identifying hazards, estimating
potential consequences, should the hazard lead to a hazardous event, estimating
the severity of these consequences, estimating the likelihood of occurrence of these
consequences, and calculating the risk level.
Risk evaluation refers to the process of making decisions on
risk reduction requirements, by comparing the estimated risks with an approved
qualitative semi-quantitative or quantitative risk tolerability criteria e.g. Risk
Classifications based on Risk Matrix, Quantitative Acceptance Criteria, etc.
Risk assessment may be undertaken using qualitative, semi-quantitative,
or quantitative methods. Each of these methods is discussed briefly below.
QUALITATIVE RISK ASSESSMENT
In the Qualitative Risk Analysis process, the risks are
analyzed based on expert judgment to judge the likelihood and impact of the
hazardous events. The estimated severity and likelihood are plotted on the
Risk Matrix to assign a risk level and category. Estimated
risks are then evaluated for required action based on the risk rank/risk level.
Where qualitative risk assessment identifies High and High
Medium risks, further detailed risk assessment using semi-quantitative or
quantitative methods for specific hazard scenarios shall be carried out to
validate and detailed assessment before deciding on risk treatment options.
This Standard shall be used for carrying out qualitative
risk assessments. The Risk Matrix includes the definitions of consequence
severity levels and likelihood. It also indicates the HSE failure frequency and
HSE likelihood to estimate the likelihood of scenarios. If the estimated
consequence severity and or likelihood vary for different categories e.g.
people, assets, etc. and then the highest severity shall be selected for
determining the overall risk level.
The four categories of
Risk Matrix:
·
High
·
High-Medium
·
Medium
·
Low
If the assessed risk level using qualitative methods
(initial screening) is High or High Medium then Semi-Quantitative or
Quantitative Risk Assessments shall be used to validate before deciding on risk
treatment options. For the project phases, this is achieved by carrying out
quantified studies for identified Major Accident Hazards which typically represent
High and High-Medium Risks.
SEMI-QUANTITATIVE
RISK ASSESSMENT
Semi-quantitative risk assessments are structured risk
assessment techniques that use simple consequence modeling techniques where
applicable to derive estimates of the severity of the hazard consequences and
event trees and failure mode assessment to derive the likelihood of hazards
resulting in hazardous events.
Quantitative estimate of failure frequencies of specific
equipment/systems e.g. pump seal, vessel failure due to overpressure, operator
response, etc. reliability data of equipment systems are used to estimate the
likelihood of events. These estimates can be combined with severity to obtain
estimates of the order of magnitude of the risk. Methods such as Scenario-Based
Risk Assessment and Layers of Protection Analysis shall be used for carrying
out semi-quantitative risk assessments. These methods make use of techniques such
as Fault Tree Analysis and Event Tree Analysis.
Risk Assessment is a systematic and structured method that
uses a combination of qualitative assessment for initial screening followed by a
semi-quantitative technique to validate the screened scenarios. The recommended
method for assessment of emerging risks which are identified through existing
process safety management systems incident investigation, management of change,
audits, inspections, maintenance programs, HSE observations, design and engineering
reviews, safety reviews, other risk assessments, etc. as part of routine
operations of existing facilities.
QUANTIFIED RISK
ASSESSMENT
Quantified risk assessment involves a numerical estimate of
the risk from a quantitative consideration of event probabilities and severity
of consequences. Quantified risk assessment yields a numerical indicator of
risk which is compared against risk tolerability criteria. Detailed Quantified
Assessment is usually carried out in various studies such as QRA etc. based on the
nature of receptors under evaluation. These studies quantify risk arising from
all major accident hazards from the plant facilities' operations. These studies
address both process and non-process hazards, however detailed key focus is on
major accident hazards arising from the process facilities considering the catastrophic
nature of the consequences.
Quantified risk assessments must be conducted where it is
mandated by legal requirements and identified as a tool to quantify the risk
based on the nature of operations to establish that risks are managed to be as
low as reasonably practicable (ALARP).
Quantitative risk assessments, specific quantitative tools,
and techniques are used for estimating the severity of the consequences and the
likelihood of the hazardous scenario occurring for various identified scenarios
within the study boundary.
Probability Determination:
Quantitative estimates of hazardous event likelihood are
usually derived using a combination of the following three approaches with full
quantification of fault and event trees, and formal expert judgment:
·
Using relevant historical data
·
Derivation through analytical modeling
techniques
·
Using expert judgment.
It is possible to derive incident frequencies directly from
historical records if the data are relevant and applicable to the particular
process hazard under consideration. One advantage of using historical data is
that it already encompasses all common relevant contributory aspects including the
reliability of equipment, human factors, and operational methods, quality of
construction, inspection, maintenance, and operation.
Modeling techniques to estimate incident frequencies from
more basic data are used when suitable historical data are not available or are
inadequate. Various techniques are available, but the most common and widely
used techniques are fault tree analysis and event tree analysis.
Physical Effects
Consequence Modelling:
Quantitative estimates of the consequences of the hazard
scenarios can be derived using appropriate consequence modeling tools.
Different mathematical models are usually used to estimate the physical effect
of the hazard. A range of models exists, from simple analytical empirical
models to complex and more rigorous mathematical models using computational
fluid dynamics. Care should be taken to ensure that the methods and models used
are appropriate to the problem being considered.
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