scholarly journals Qualitative assessment of deterioration embankment dam using index condition and annual probability of failure (APF) using event tree method

2021 ◽  
Vol 794 (1) ◽  
pp. 012060
Author(s):  
Juliastuti ◽  
B. Thoyibahri ◽  
C Cahyono ◽  
O. Setyandito
Keyword(s):  
Probability Of Failure ◽  
Qualitative Assessment ◽  
Event Tree ◽  
Embankment Dam ◽  
Annual Probability ◽  
Tree Method ◽  
Index Condition

scholarly journals PENILAIAN RISIKO KEGAGALAN BENDUNGAN KEDUNGOMBO SEBAGAI DASAR PRIORITAS PEMELIHARAAN BENDUNGAN

2021 ◽  
Vol 4 (3) ◽  
pp. 557
Author(s):  
Rais Buldan ◽  
Suharyanto Suharyanto ◽  
Sriyana Sriyana
Keyword(s):  
Traditional Method ◽  
Probability Of Failure ◽  
Event Tree ◽  
Acceptable Risk ◽  
Safety Hazards ◽  
Performance Function ◽  
Priority Systems ◽  
Risk Probability ◽  
The Status ◽  
Tree Method

A dams must always be maintained for their performance, function, and safety, so it is necessary to carry out various maintenance, repairs, and rehabilitation on dams that have been built and operating. Priority systems for the implementation of repair and rehabilitation of dams can be arranged based on the status of safety hazards or the level of risk of failure due to natural disasters or other consequences. Based on this, it is necessary to carry out an assessment of the dam to estimate the magnitude of the risk to the dam. According to the Risk Analysis Guidelines, the estimation of the probability of failure can be done using two methods, namely the traditional method and the event tree method. Based on the results of assessment analysis, the risk probability of the Kedungombo Dam with the traditional method and the event tree method is 4,010 x 10-1 and 1,548 x 10-3 where the acceptable limit conditions for the existing dam are a maximum of 1,000 x 10-5. The risk probability value of the Kedungombo Dam does not meet the requirements of an acceptable risk value. Therefore, it is necessary to recommend risk reduction for the risk assessment results. ABSTRAKBendungan harus selalu dijaga kinerja operasi, fungsi, dan keamanannya, sehingga perlu dilakukan berbagai kegiatan pemeliharaan, perbaikan, dan rehabilitasi pada bendungan yang sudah terbangun dan beroperasi. Sistem prioritas pada pelaksanaan kegiatan perbaikan dan rehabilitasi pada bendungan dapat disusun berdasarkan status bahaya bendungan dari segi keamanan atau besarnya risiko terhadap kegagalan bendungan akibat bencana alam maupun akibat lain. Berdasarkan hal tersebut, maka perlu dilakukan penilaian risiko pada bendungan untuk memperkirakan besarnya risiko bahaya pada bendungan. Berdasarkan Pedoman Analisis Risiko, perkiraan probabilitas kegagalan dapat dilakukan dengan dua metode yaitu metode tradisional dan metode pohon kejadian (event tree). Berdasarkan hasil analisis penilaian risiko, probabilitas risiko Bendungan Kedungombo metode tradisional dan metode pohon kejadian sebesar 4,010 x 10-1 dan 1,548 x 10-3 dimana syarat batas yang dapat diterima untuk bendungan eksisting maksimum 1,000 x 10-5. Nilai probabilitas risiko Bendungan Kedungombo tidak memenihi syarat nilai risiko yang dapat diterima. Dengan demikian, diperlukan rekomendasi tindakan pengurangan risiko untuk risiko hasil penilaian tersebut. 

Predictive Assessment of External Corrosion on Transmission Pipelines

2008 ◽  
Author(s):  
Gae¨l Pognonec ◽  
Vincent Gaschignard ◽  
Philippe Notarianni
Keyword(s):  
Growth Rate ◽  
Oil And Gas ◽  
Electrochemical Corrosion ◽  
Software Tool ◽  
Probability Of Failure ◽  
Entropy Method ◽  
Probabilistic Methods ◽  
Optimal Interval ◽  
Annual Probability ◽  
Cross Entropy Method

Oil and Gas operators have to deal with the ageing process of their transmission pipeline grid. Some of these pipelines can be inspected using In Line Inspection (ILI) tools. In order to maintain an acceptable integrity level, re-inspection operations have to be performed. This process needs to be optimized in terms of resources and cost. Gaz de France R&D Division has developed a methodology which prioritizes rehabilitation operations on a pipeline after in-line inspections, and determines the optimal interval for re-inspection. A reliable help decision software tool which applies the methodology has also been developed. Dealing with defects assimilated to external electrochemical corrosion, the developed methodology is based on: • pigs information in order to assess a probable corrosion growth rate; • probabilistic distribution of input parameters (geometrical characteristics of defects, characteristics of the pipe and corrosion growth rate); • probabilistic methods of calculation : the probability of failure is calculated with the Monte-Carlo method. The convergence of the calculation is accelerated with the Cross Entropy method. The calculation results take the form of three probabilities of failure: • a punctual probability of failure for each defect; • an annual probability of failure for each defect; • an annual probability of failure per kilometer of pipe. To interpret the results, the annual probability of failure per kilometer of pipe is then compared with threshold values.

Risk Assessment of Enterprise Merger and Acquisition Based on Event Tree Method and Fuzzy Set Theory

2013 ◽  
Vol 13 (21) ◽  
pp. 4819-4825 ◽  
Author(s):  
Guang-Rong Li ◽  
Chun-He Li ◽  
Xiu-Hong Niu ◽  
Li-Ping Yang
Keyword(s):  
Risk Assessment ◽  
Set Theory ◽  
Fuzzy Set ◽  
Fuzzy Set Theory ◽  
Merger And Acquisition ◽  
Event Tree ◽  
Tree Method

Estimation on probability of radiological hazards for nuclear facilities decommissioning based on fuzzy and event tree method

2011 ◽  
Vol 38 (11) ◽  
pp. 2606-2611 ◽  
Author(s):  
Kwan-Seong Jeong ◽  
Kune-Woo Lee ◽  
Seong-Young Jeong ◽  
Hyeon-Kyo Lim
Keyword(s):  
Event Tree ◽  
Nuclear Facilities ◽  
Radiological Hazards ◽  
Tree Method

Simplified Strength Reliability and Integrity Analysis of TTRs

2014 ◽  
Author(s):  
Mir Emad Mousavi ◽  
Sanjeev Upadhye ◽  
Kevin Haverty
Keyword(s):  
Extreme Events ◽  
Structural Reliability ◽  
Probability Distributions ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Cost Effective ◽  
Probability Of Failure ◽  
Annual Probability ◽  
Reliability Methods ◽  
Integrity Analysis

The design of riser systems can be improved if structural reliability methods are used to assess their safety and integrity and confirm that such design meets a target annual probability of failure. TTRs are typically multi–bore assemblies involving several sub-assemblies. The failure of any of the components of a TTR under extreme or service environmental conditions can lead to an immediate failure of the entire assembly and impose a direct risk of damaging the wellheads, conductors, casing and tubing hangers, or other subsea equipment, because they are installed directly on top of the wellhead. However, the actual strength safety of the TTR cannot be examined unless after it is installed and examined under extreme events. Because of the numerous uncertainties associated with the design of TTRs, a probabilistic approach based on structural reliability methods can account for many of those uncertainties and serve as a basis for their reliable and cost-effective design. In turn, a comprehensive reliability assessment of a TTR requires extensive analysis that is considerably more complex and time consuming compared to a conventional deterministic-based analysis. This paper presents a probabilistic-based simplified methodology for the strength reliability assessment of TTR systems. In this method, marginal values on some uncertain model inputs are considered similar to the conventional analysis methods but, some key random variables related to environmental demands and component capacities are considered with their associated probability distributions. As a result, this method can be used to estimate the minimum level of safety of the TTR under extreme events. Additionally, results of the proposed method are discussed for integrity analysis and integrity-based optimal design of the TTR system, which compare the safety of the TTR components and estimate the component Optimality Factors for improving the design integrity and meeting a target minimum annual probability of failure.

Analysis of domino effect in the process industry using the event tree method

2017 ◽  
Vol 97 ◽  
pp. 10-19 ◽  
Author(s):  
Nassim Alileche ◽  
Damien Olivier ◽  
Lionel Estel ◽  
Valerio Cozzani
Keyword(s):  
Process Industry ◽  
Event Tree ◽  
Domino Effect ◽  
Tree Method

scholarly journals IT RISK IDENTIFICATION AND ASSESSMENT METHODOLOGY

2017 ◽  
Vol 2 ◽  
pp. 124
Author(s):  
Oskars Podziņš ◽  
Andrejs Romānovs
Keyword(s):  
Risk Assessment ◽  
Impact Analysis ◽  
Risk Identification ◽  
The Other ◽  
Qualitative Assessment ◽  
Event Tree ◽  
Structured Interviews ◽  
Event Tree Analysis ◽  
Tree Analysis ◽  
Other Hand

There are numerous methods for risk identification and risk assessment phases. Which for risk identification includes historical and systematic approach and inductive or theoretical analysis. One of the main reasons why risk identification is very helpful is that it provides justification in many cases for any large IT investment and other large undertakings. Without it organization probably wouldn’t be able to come to conclusion. Also in this phase business recognize the threats, vulnerabilities, and assets associated with its IT systems. Together with risk assessment phase risk management specialist is responsible for determining asset value, what's the value of the asset business is protecting, and risk acceptance level. Risk assessment on the other hand examines impact or consequence, as well as examines and evaluates the likelihood or probability of that adverse event happening. Risk assessment includes methods like Bayesian analysis, Bow Tie Analysis, brainstorming or structured interviews, business impact analysis, cause and consequence, cause-and-effect analysis, Delphi method, event tree analysis, fault tree analysis, hazard analysis, hazard and operational studies, and finally structured what if technique or SWIFT process. Risk assessment has two distinctive assessment types- quantitative and qualitative assessment. Quantitative assessment tries to put a monetary value on all risks. Qualitative assessment on the other hand rather look at it from a range of values like low, medium, high. The results of these phases are going to be documented in the risk assessment report and reported to senior management.

ACCIDENTAL FALLS FROM ELEVATED SURFACES IN INFANTS FROM BIRTH TO ONE YEAR OF AGE

PEDIATRICS ◽  
1969 ◽  
Vol 44 (5) ◽  
pp. 869-876
Author(s):  
Harvey Kravitz ◽  
Gerald Driessen ◽  
Raymond Gomberg ◽  
Alvin Korach
Keyword(s):  
Cultural Differences ◽  
Statistical Treatment ◽  
Event Tree ◽  
Pediatric Practice ◽  
Additional Information ◽  
Strong Current ◽  
One Year ◽  
Injury Control ◽  
Tree Method ◽  
Investigative Criteria

This work is typical of the efforts of the gifted practitioner concerned with an important problem encountered in pediatric practice. It has all the limitations which time and sampling impose and does not satisfy the more precise investigative criteria for control populations, statistical treatment and other considerations which further studies by this group may encompass. It represents an effort which seeks a practical solution and it enlists allies in a well known safety organization. It is the method of collaboration and the clues that are developed which makes this paper a vital contribution. The practitioner requires supportive workers in this type of investigation, but is in a superb position to give additional information about the child and his family, and to implement findings that might be related to prevention. The "event tree" method of study and action which is proposed and illustrated offers a model for injury control of many types. Community workers who are concerned about the problem of falls as the leading method of childhood injury are hereby offered a useful method of study which does not require extensive or complicated efforts. The leads that the paper offers with respect to cultural differences in types of falls and circumstances should be explored. It is unclear either in this work or in the literature whether the method of control posters, campaigns, etc. are indeed effective or not. All existing methods of fall control should be encouraged as they raise the level of awareness of the hazards to children, but a number of investigators have indicated that it is the mother's attitude and distractions from childbearing which offer a strong current of causation. Approaches with the same population using evaluated techniques suggested by the authors are a next step.

Hybrid Event Tree Analysis of Ship Grounding Probability

2003 ◽  
Author(s):  
Dianqing Li ◽  
Wenyong Tang ◽  
Shengkun Zhang
Keyword(s):  
Failure Probability ◽  
Human Error ◽  
Sensitivity Index ◽  
Event Tree ◽  
Fuzzy Probability ◽  
Event Tree Analysis ◽  
Probability Of Occurrence ◽  
Ship Grounding ◽  
Tree Method ◽  
Hybrid Event

The probability of occurrence of human-error-dominated event can not be effectively handled by using conventional event tree method. Furthermore, it is impossible to consider the sensitivity and uncertainty of basic events’ probabilities in conventional event tree method. To overcome these disadvantages, the concepts of the fuzzy error rate and the fuzzy error possibility were introduced to represent the failure probability of human-error-dominated event, while the fuzzy probability was used to represent the failure probability of non-human-error-dominated event. Based on them, the fuzzy probability of ship grounding with piloting failure was calculated by hybrid event tree method. Moreover, the fuzzy sensitivity index and the fuzzy uncertainty index were defined. Some grounding probability reducing measures were verified by sensitivity and uncertainty analysis. The results indicate that the proposed approach is very useful in analyzing the probability of occurrence of human-error-dominated event.

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