Qualitative risk analysis

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Qualitative risk analysis is a technique used to quantify risk associated with a particular hazard. Risk assessment is used for uncertain events that could have many outcomes and for which there could be significant consequences. Risk is a function of probability of an event (a particular hazard occurring) and the consequences given the event occurs. Probability refers to the likelihood that a hazard will occur. In a qualitative assessment, probability and consequence are not numerically estimated, but are evaluated verbally using qualifiers like high likelihood, low likelihood, etc. Qualitative assessments are good for screening level assessments when comparing/screening multiple alternatives or for when sufficient data is not available to support numerical probability or consequence estimates. Once numbers are inserted into the analysis (either by quantifying the likelihood of a hazard or quantifying the consequences) the analysis transitions to a semi-quantitative or quantitative risk assessment.

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Qualitative techniques

There are several techniques when performing qualitative risk analysis to determine the probability and impact of risks, including the following:

Developing rating scales

Assigning probability and impacts to risks is a subjective exercise. Some of this subjectivity can be eliminated by developing rating scales that are agreed upon by the sponsor, project manager, and key team members. Some organizations, particularly those that have project management offices responsible for overseeing all projects, have rating scales already developed. [1]

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Risk management Set of measures for the systematic identification, analysis, assessment, monitoring and control of risks

Risk management is the identification, evaluation, and prioritization of risks followed by coordinated and economical application of resources to minimize, monitor, and control the probability or impact of unfortunate events or to maximize the realization of opportunities.

Safety engineering Engineering discipline which assures that engineered systems provide acceptable levels of safety

Safety engineering is an engineering discipline which assures that engineered systems provide acceptable levels of safety. It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering. Safety engineering assures that a life-critical system behaves as needed, even when components fail.

Fault tree analysis Failure analysis system used in safety engineering and reliability engineering

Fault tree analysis (FTA) is a top-down, deductive failure analysis in which an undesired state of a system is analyzed using Boolean logic to combine a series of lower-level events. This analysis method is mainly used in safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk and to determine event rates of a safety accident or a particular system level (functional) failure. FTA is used in the aerospace, nuclear power, chemical and process, pharmaceutical, petrochemical and other high-hazard industries; but is also used in fields as diverse as risk factor identification relating to social service system failure. FTA is also used in software engineering for debugging purposes and is closely related to cause-elimination technique used to detect bugs.

Broadly speaking, a risk assessment is the combined effort of:

  1. identifying and analyzing potential (future) events that may negatively impact individuals, assets, and/or the environment ; and
  2. making judgments "on the tolerability of the risk on the basis of a risk analysis" while considering influencing factors.

Probabilistic risk assessment (PRA) is a systematic and comprehensive methodology to evaluate risks associated with a complex engineered technological entity or the effects of stressors on the environment for example.

A hazard analysis is used as the first step in a process used to assess risk. The result of a hazard analysis is the identification of different type of hazards. A hazard is a potential condition and exists or not. It may in single existence or in combination with other hazards and conditions become an actual Functional Failure or Accident (Mishap). The way this exactly happens in one particular sequence is called a scenario. This scenario has a probability of occurrence. Often a system has many potential failure scenarios. It also is assigned a classification, based on the worst case severity of the end condition. Risk is the combination of probability and severity. Preliminary risk levels can be provided in the hazard analysis. The validation, more precise prediction (verification) and acceptance of risk is determined in the Risk assessment (analysis). The main goal of both is to provide the best selection of means of controlling or eliminating the risk. The term is used in several engineering specialties, including avionics, chemical process safety, safety engineering, reliability engineering and food safety.

Risk register

A risk register (PRINCE2) is a document used as a risk management tool and to fulfill regulatory compliance acting as a repository for all risks identified and includes additional information about each risk, e.g. nature of the risk, reference and owner, mitigation measures. It can be displayed as a scatterplot or as a table.

A risk matrix is a matrix that is used during risk assessment to define the level of risk by considering the category of probability or likelihood against the category of consequence severity. This is a simple mechanism to increase visibility of risks and assist management decision making.

Event chain methodology Network analysis technique

Event chain methodology is a network analysis technique that is focused on identifying and managing events and relationship between them that affect project schedules. It is an uncertainty modeling schedule technique. Event chain methodology is an extension of quantitative project risk analysis with Monte Carlo simulations. It is the next advance beyond critical path method and critical chain project management. Event chain methodology tries to mitigate the effect of motivational and cognitive biases in estimating and scheduling. It improves accuracy of risk assessment and helps to generate more realistic risk adjusted project schedules.

A job safety analysis (JSA) is a procedure which helps integrate accepted safety and health principles and practices into a particular task or job operation. In a JSA, each basic step of the job is to identify potential hazards and to recommend the safest way to do the job. Other terms used to describe this procedure are job hazard analysis (JHA) and job hazard breakdown.

Absolute probability judgement is a technique used in the field of human reliability assessment (HRA), for the purposes of evaluating the probability of a human error occurring throughout the completion of a specific task. From such analyses measures can then be taken to reduce the likelihood of errors occurring within a system and therefore lead to an improvement in the overall levels of safety. There exist three primary reasons for conducting an HRA; error identification, error quantification and error reduction. As there exist a number of techniques used for such purposes, they can be split into one of two classifications; first generation techniques and second generation techniques. First generation techniques work on the basis of the simple dichotomy of 'fits/doesn't fit' in the matching of the error situation in context with related error identification and quantification and second generation techniques are more theory based in their assessment and quantification of errors. 'HRA techniques have been utilised in a range of industries including healthcare, engineering, nuclear, transportation and business sector; each technique has varying uses within different disciplines.

The technique for human error-rate prediction (THERP) is a technique used in the field of human reliability assessment (HRA), for the purposes of evaluating the probability of a human error occurring throughout the completion of a specific task. From such analyses measures can then be taken to reduce the likelihood of errors occurring within a system and therefore lead to an improvement in the overall levels of safety. There exist three primary reasons for conducting an HRA: error identification, error quantification and error reduction. As there exist a number of techniques used for such purposes, they can be split into one of two classifications: first-generation techniques and second-generation techniques. First-generation techniques work on the basis of the simple dichotomy of ‘fits/doesn’t fit’ in matching an error situation in context with related error identification and quantification. Second generation techniques are more theory-based in their assessment and quantification of errors. ‘HRA techniques have been utilised for various applications in a range of disciplines and industries including healthcare, engineering, nuclear, transportation and business.

Success Likelihood Index Method (SLIM) is a technique used in the field of Human reliability Assessment (HRA), for the purposes of evaluating the probability of a human error occurring throughout the completion of a specific task. From such analyses measures can then be taken to reduce the likelihood of errors occurring within a system and therefore lead to an improvement in the overall levels of safety. There exist three primary reasons for conducting an HRA; error identification, error quantification and error reduction. As there exist a number of techniques used for such purposes, they can be split into one of two classifications; first generation techniques and second generation techniques. First generation techniques work on the basis of the simple dichotomy of ‘fits/doesn’t fit’ in the matching of the error situation in context with related error identification and quantification and second generation techniques are more theory based in their assessment and quantification of errors. ‘HRA techniques have been utilised in a range of industries including healthcare, engineering, nuclear, transportation and business sector; each technique has varying uses within different disciplines.

Risk Breakdown Structure (RBS) - A hierarchically organised depiction of the identified project risks arranged by category.

Radiation dose reconstruction

Radiation dose reconstruction refers to the process of estimating radiation doses that were received by individuals or populations in the past as a result of particular exposure situations of concern. The basic principle of radiation dose reconstruction is to characterize the radiation environment to which individuals have been exposed using available information. In cases where radiation exposures can not be fully characterized based on available data, default values based on reasonable scientific assumptions can be used as substitutes. The extent to which the default values are used depends on the purpose of the reconstruction(s) being undertaken.

A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them, even just theoretically, to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk, a term often used synonymously in colloquial speech.

In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value, often focusing on negative, undesirable consequences. Many different definitions have been proposed. The international standard definition of risk for common understanding in different applications is “effect of uncertainty on objectives”.

Bayesian inference in marketing

In marketing, Bayesian inference allows for decision making and market research evaluation under uncertainty and with limited data.

Event tree analysis (ETA) is a forward, top-down, logical modeling technique for both success and failure that explores responses through a single initiating event and lays a path for assessing probabilities of the outcomes and overall system analysis. This analysis technique is used to analyze the effects of functioning or failed systems given that an event has occurred. ETA is a powerful tool that will identify all consequences of a system that have a probability of occurring after an initiating event that can be applied to a wide range of systems including: nuclear power plants, spacecraft, and chemical plants. This technique may be applied to a system early in the design process to identify potential issues that may arise, rather than correcting the issues after they occur. With this forward logic process, use of ETA as a tool in risk assessment can help to prevent negative outcomes from occurring, by providing a risk assessor with the probability of occurrence. ETA uses a type of modeling technique called event tree, which branches events from one single event using Boolean logic.

An occupational risk assessment is an evaluation of how much potential danger a hazard can have to a person in a workplace environment. The assessment takes into account possible scenarios in addition to the probability of their occurrence, and the results. The five types of hazards to be aware of are safety, chemicals, biological, physical, and ergonomic.

References

  1. Kim Heldman, PMP, Project Manager's Spotlight on Risk Management,p125,126