Bayesian Updating of Aircraft Risk Assessments Using Results of Inspection

2014 ◽  
Vol 891-892 ◽  
pp. 1047-1052
Author(s):  
Ribelito F. Torregosa ◽  
Wei Ping Hu
Keyword(s):  
Risk Assessment ◽  
Bayesian Inference ◽  
Risk Analysis ◽  
Size Distribution ◽  
Probability Of Failure ◽  
Flaw Size ◽  
Risk Assessments ◽  
Structural Failure ◽  
Risk Of Failure ◽  
Calculated Risk

This paper illustrates a technique that may be used to evaluate the risk of structural failure of each aircraft in a fleet when a crack has been detected in a particular member aircraft, or the risk of failure for that member has become too high. When a crack is detected, the calculated risk of failure for other aircraft in the fleet will increase significantly, and the aircraft operators need to decide which aircraft should be temporarily grounded for unscheduled inspection and which ones be allowed to fly. The proposed method applies the Bayesian inference to update the risk assessment by updating the equivalent initial flaw size distribution, which is one of the key inputs for risk analysis. To illustrate the method, a hypothetical fleet aircraft is considered and the single flight probability of failure of each aircraft in the fleet is revised after the occurrence of a failure in one fleet aircraft.

On the Safety of Fixed Offshore Structures, Failure Paths and Barriers

2002 ◽  
Author(s):  
Gerhard Ersdal
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Steel Structure ◽  
Offshore Structures ◽  
Point Of View ◽  
Structural Safety ◽  
General Level ◽  
Structural Failure ◽  
Offshore Structure ◽  
Protection Strategies

In order to ensure the safety of an offshore structure it is important to identify and maintain the barriers preventing hazardous events. Also, when monitoring the safety, the monitoring should be regarding how well these barriers are functioning, and utilise these to reassess the safety of the structure over time. The purpose of this paper is to apply a well-known method in risk assessment, Haddon’s energy and barrier model, to a new area; structural safety. The purposes of this exercise are to look at the structural safety from a risk assessment point of view, and to use this to identify and give an overview of the existing barriers. Furthermore, the purposes are to evaluate the efficiency and redundancy of these barriers, and to use this to evaluate the safety of offshore structures. This paper will analyse the safety of a fixed offshore structure through a qualitative approach. A possible event chart for a fixed offshore installation during operation in storms is established and analysed. Some of the root causes for potential structural failure are identified. These root-causes are kept on a general level, but considered in more detail than often seen in risk analysis. Hazards that are normally included in risk analysis, like boat collisions, fire, explosions, and dropped objects are not evaluated. Hazards that are evaluated are structural failure due to wave loading, fatigue damage, aging, and gross errors in design, fabrication, installation and operation. In order to identify the barriers (hazard reduction strategies, physical barriers and vulnerable target protection strategies), the different failure paths in the event chart are then analysed using Haddon’s ten preventive strategies for reducing damage from hazards. As an example a fixed offshore steel structure is used. A list of proposed barriers that influence the safety of such a fixed offshore installation are presented, and methods to measure these barriers are discussed.

Initiating and Managing Risk Assessments within a Risk Analysis Framework: FDA/CFSAN'S Practical Approach

2004 ◽  
Vol 67 (9) ◽  
pp. 2058-2062 ◽  
Author(s):  
ROBERT L. BUCHANAN ◽  
SHERRI DENNIS ◽  
MARIANNE MILIOTIS
Keyword(s):  
Risk Assessment ◽  
Decision Making ◽  
Risk Management ◽  
Risk Analysis ◽  
Risk Assessments ◽  
Analysis Framework ◽  
Regulatory Decision ◽  
Managing Risk ◽  
Risk Managers ◽  
The U.S

Management of risk analysis involves the integration and coordination of activities associated with risk assessment, risk management, and risk communication. Risk analysis is used to guide regulatory decision making, including trade decisions at national and international levels. The U.S. Food and Drug Administration Center for Food Safety and Applied Nutrition (CFSAN) formed a working group to evaluate and improve the quality and consistency of major risk assessments conducted by the Center. Drawing on risk analysis experiences, CFSAN developed a practical framework for initiating and managing risk assessments, including addressing issues related to (i) commissioning a risk assessment, (ii) interactions between risk managers and risk assessors, and (iii) peer review.

Risks of Risk Decisions

Science ◽  
1980 ◽  
Vol 208 (4448) ◽  
pp. 1114-1119 ◽  
Author(s):  
Chauncey Starr ◽  
Chris Whipple
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Decision Process ◽  
Cost Benefit ◽  
Risk Assessments ◽  
Individual Risk ◽  
Financial Cost ◽  
Technological Risk ◽  
Risk Criteria ◽  
Analytical Approaches

The analytical approaches utilized for evaluating the acceptability of technological risk originate from analogies to financial cost-benefit risk analysis. These analogies appear generally valid for viewing risk from a societal basis, but are not applicable to individual risk assessments. Conflicts arising from these different views of risk assessment provide insights to the origins of individual, intuitive evaluations. Societal risk decisions made under conflict represent political compromises, and the resulting decision process creates substantial conflict costs. The pragmatic use of quantitative risk criteria (safety targets) may be useful in reducing these costs.

scholarly journals Methodologies in measuring risk of financial statements

2010 ◽  
pp. 117-120
Author(s):  
Vilmos Wágner
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Utility Theory ◽  
Financial Statements ◽  
Risk Assessments ◽  
Assessment Methodology ◽  
Optimum Point ◽  
Multi Attribute Utility Theory ◽  
Financial Audit ◽  
Risk Assessment Methodology

Aim of financial statements’ risk analysis is to optimally allocate the audit resources. That optimum point can be reached, if we achieve maximum possibility of recovery of material risks. There are more than one procedures exist for researching of optimum point or risk assessment in other word, and they are needed to use even parallel. In order to take into consideration effects of risk we need to measure them somehow. At risk assessments risks are usually some kind of result of impact and possibility. Knowledge and measurement of impacts and possibilities are far not enough for assessment of certain risks. In this study I will present a possible usable risk assessment methodology for financial audit activities with using Multi Attribute Utility Theory (MAUT in the followings).

Inspection interval optimization of aircraft landing gear component based on risk assessment using equivalent initial flaw size distribution method

2021 ◽  
pp. 147592172110336
Author(s):  
Youngjun Lee ◽  
Jongwoon Park ◽  
Dooyoul Lee
Keyword(s):  
Crack Propagation ◽  
Size Distribution ◽  
Crack Growth ◽  
Landing Gear ◽  
Flaw Size ◽  
Distribution Method ◽  
Aircraft Landing ◽  
Inspection Interval ◽  
Aircraft Landing Gear ◽  
Calculated Risk

The nondestructive inspection interval is highly related with both system reliability and maintenance burden. Conventional inspection interval decision criteria based on the deterministic crack propagation analysis could require too much frequent inspection or sometimes occur structural failure owing to the rapid crack propagation than expected. The stochastic crack growth analysis method was proposed to compensate for the shortcomings of the deterministic analysis. This research studied the crack growth of aircraft landing gear components based on the equivalent initial flaw size distribution algorithm, and then we assessed failure risk. The calculated risk was validated using Monte-Carlo simulation, and finally, the optimum inspection interval was proposed to satisfy the US Airforce risk management criteria.

Comparison of SCORE and Reynolds cardiovascular risk assessments in a cohort without cardiovascular disease

2013 ◽  
Vol 154 (43) ◽  
pp. 1709-1712 ◽  
Author(s):  
Csaba Móczár
Keyword(s):  
Cardiovascular Disease ◽  
Risk Assessment ◽  
Cardiovascular Risk ◽  
Screening Program ◽  
Risk Group ◽  
Scoring Systems ◽  
High Risk Group ◽  
Risk Assessments ◽  
Gender And Age ◽  
Medium Risk

Introduction: Cardiovascular risk assessment may help in the identification of symptom-free subjects with high cardiovascular risk. Aim: The author studied the correlation between SCORE and Reynolds risk assessment systems based on data from the cardiovascular risk screening program carried out in subjects without cardiovascular disease. Method: Data obtained from 4462 subjects (1977 men and 2485 women; mean age, 47,4 years) were analysed. The comparison was based on risk categories of the SCORE system. Results: There was a strong correlation between the two scoring systems in the low risk population (under <2% SCORE risk the Spearman rho = 1, p < 0.001). A weak correlation was found in the medium risk group (between 3–4% the Spearman rho = 0.59–0.49, p < 0.001 and between 10–14% the Spearman rho = 0.42, ns.) and a stronger correlation in the high risk group (>15% the Spearmen rho = 0.8, p = 0.017). When correlations were analysed in gender and age categories, the weakest correlation was detected in medium risk women over 40 years of age. In cases when the differences between the two scoring systems were significant, the hsCRP levels were significantly higher (4.1 vs. 5.67 mg/L, p < 0.001). Conclusions: Introduction of hsCRP into cardiovascular risk assessments can refine the risk status of symptom-free subjects, especially among intermediate risk middle-age women (two-step risk assessment). Orv. Hetil., 154 (43), 1709–1712.

Designing Risk Qualitative Assessment on Fiber Optic Instalation Project in Indonesia

2018 ◽  
Vol 2 (01) ◽  
Author(s):  
Devi Pratami
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Fiber Optic ◽  
Qualitative Assessment ◽  
Quality And Safety ◽  
Project Implementation ◽  
Cost Impact ◽  
Implementation Assessment ◽  
The Impact ◽  
Impact Cost

A project always has risks that can lead to project failure. In the project, a risk analysis is required to provide an evaluation for the project to proceed as planned. In the event of inadequate planning and ineffective control, it will result in irregularities identified as a risk to the project. This study aims to analyze the qualitative risk on Fiber Optic Installaion project in Sukabumi, West Java, Indonesia. In addition, risk assessment is undertaken on project implementation. Assessment of risk using the impact and probability to measure the impact of risk occurrence. The impacts are more detailed by classified by time impact, cost impact, quality impact, safety and security impact, proximity. The result is there are 36 risk that may occur and mostly risks are associaated by quality and safety&security impact.

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