KEY ELEMENTS OF RISK ASSESSMENT
Risk assessment is the scientific process of
collecting and analysing scientific data to describe the characteristic of risk
which can take up many forms such as physical hazard, mechanical hazard,
chemical hazards and biological hazards etc.
Every workplace should conduct risk
assessments for all routine and non-routine operations carried out under
various environmental situations, e.g., weather and soil conditions. Routine
operations include activities such as preparatory and troubleshooting work
activities. Non-routine operations include commissioning, repair and
maintenance of plants
There are many risk assessment methods
available in the industry and the choice of method depends very much on the
purpose and scope of the available information or data used in an assessment as
well as what we want to achieve at the end of
a risk assessment study
No matter which methods of risk assessment
that you use, all methods should comprise the 3 basic steps of ; Hazard Identification, Risk Evaluation and
Risk Control..
Hazard
Identification is the process of identifying hazards
in order to plan for, avoid, or mitigate their impacts and for decision making
purposes. Hazard identification is an
important step in risk assessment and risk management
Hazard identification builds the foundation
on which subsequent quantitative frequency and/or consequence estimates are
made. We may have considered chemical, physical, mechanical and biological
properties can present a hazard during a fault or failure conditions. But it is
not always possible to be sure that all situations have been taken into
consideration.
The simplest systematic approach to identify
hazard is the use of checklist. Checklists are lists of known hazards or hazard
causes that have been derived from past experience.
The past experience could be previous risk assessments of similar systems or operations,
or from actual incidents that have occurred in the past. This technique
involves the systematic use of an appropriate checklist and the consideration
of each item on the checklist for possible applicability to a particular
system.
Checklists should always be validated for applicability prior to use.
Advantages
of using checklist to identify hazard
They can be used by non-system experts.
They capture a wide range of previous
knowledge and experience.
They ensure that common and more obvious
problems are not overlooked.
Disadvantages
of using checklist to identify hazard
They are of limited use when dealing with
novel systems.
They can inhibit imagination in the hazards
identification process.
They would miss hazards that have not been
previously seen.
Consequence
Analysis
Consequence Analysis is the process of
examining the possible effects of a planned activity, for example the possible
risks to the environment that may be caused by building work
Consequence analysis involves 4 basic
activities which include:
- Characterizing the source of the release of material or energy associated with the hazard being analyzed
- Measuring through costly experiments or estimating using models and correlations the transport of the material and/or the propagation of the energy in the environment to a target of interest
- Identifying the effects of the propagation of the energy or material on the target of interest
- Quantifying the health, safety ,environmental, or economic impacts on the target of interest
Risk
Analysis
Risk Analysis is a component of risk
management, it consists of
(1) Identification of possible negative
external and internal conditions, events, or situations,
(2) Determination of cause-and-effect
(causal) relationships between probable happenings, their magnitude, and likely
outcomes,
(3) Evaluation of various outcomes under
different assumptions, and under different probabilities that each outcome will
take place,
(4) Application of qualitative and
quantitative techniques to reduce uncertainty of the outcomes and associated
costs, liabilities, or losses.
Successful QRA provide data and information
that allow us to increase our wisdom and understanding of the risk of a
particular activity.
To interpret the QRA results would require us
to review the analysis objectives For example if our objective is to identify
the most important contributors to potential accidents, then the results may be
completely unsuitable for presentation to zoning commission interested in the
total risk of a toxic material release.
Hence it is important and essential that QRA
be interpreted only in the context of the study objective.
Four essential area largely determine our
success in capitalizing on high quality QRA results and they are namely;
- Presenting the results in perspective
- Recognising the factors that influence perceptions of the meaning of the results
- Credibly communicating risk information in the public arena
- Avoiding common pitfalls in using the results for making the right decision
