RA Key Elements

Risk assessment is the scientific process of collecting and analyzing 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 Recognizing 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 Limitation in Risk Assessment When using the QRA results for decision making purposes or when chartering a QRA Study, we must recognize and respect the limitation in risk assessment due to the fact that quantitative risk analysis is subject to several theoretical limitation lists.

Completeness	There can never be a guarantee that all accident situations, causes, and effects have been considered
Model Validity	Probabilistic failure models cannot be verified. Physical phenomena are observed in experiments and used in model correlations, but models are, at best, approximations of specific accident conditions
Accuracy/Uncertainty	The lack of specific data on component failure characteristics, chemical and physical properties and phenomena severely limit accuracy and can produce large uncertainties
Reproducibility	Various aspects of QRA are highly subjective-the results are very sensitive to the analysts assumptions. The same problem, using identical data and models, may generate widely varying answers when analyzed by different experts
Skill Unavailable	The accuracy and corresponding uncertainty of a risk estimate depend heavily upon the expertise and judgement of the analyst
Inscrutability	The inherent nature of QRA makes the results difficult to understand and use