scholarly journals Importance analysis of fault trees by visual inspection

2021 ◽  
Author(s):  
Gurvinder Kaur Bains
Keyword(s):  
Visual Inspection ◽  
High Reliability ◽  
Fault Tree ◽  
Software Tools ◽  
Simple Arithmetic ◽  
Fault Trees ◽  
Repeated Events ◽  
Importance Analysis

To achieve high reliability for any system, it is necessary to identify the components and the subsystems that have the greatest impact on its reliability. Such items can be identified using importance measures that rank the items quantitatively according to their contribution to the system unreliability. Taking into consideration the complexity and time involved in computing these measures we have proposed an algorithm that can pinpoint the most important component just by visually inspecting the fault tree. Calculations whenever required, involve simple arithmetic. It gives the user freedom from the complex calculations, save their time and performs the intended task without the use of software tools. Then the generalization of this work has been proposed that ranks the components of the fault tree. We have illustrated both the algorithms for the fault trees without as well as with repeated events.

scholarly journals Importance analysis of fault trees by visual inspection

2021 ◽  
Author(s):  
Gurvinder Kaur Bains
Keyword(s):  
Visual Inspection ◽  
High Reliability ◽  
Fault Tree ◽  
Software Tools ◽  
Simple Arithmetic ◽  
Fault Trees ◽  
Repeated Events ◽  
Importance Analysis

To achieve high reliability for any system, it is necessary to identify the components and the subsystems that have the greatest impact on its reliability. Such items can be identified using importance measures that rank the items quantitatively according to their contribution to the system unreliability. Taking into consideration the complexity and time involved in computing these measures we have proposed an algorithm that can pinpoint the most important component just by visually inspecting the fault tree. Calculations whenever required, involve simple arithmetic. It gives the user freedom from the complex calculations, save their time and performs the intended task without the use of software tools. Then the generalization of this work has been proposed that ranks the components of the fault tree. We have illustrated both the algorithms for the fault trees without as well as with repeated events.

Automatic Fault Tree Generation From Multidisciplinary Dependency Models for Early Failure Propagation Assessment

2018 ◽  
Author(s):  
Nikolaos Papakonstantinou ◽  
Joonas Linnosmaa ◽  
Jarmo Alanen ◽  
Bryan O'Halloran
Keyword(s):  
Failure Modes ◽  
Cooling System ◽  
Fault Tree ◽  
System Engineering ◽  
Automatic Generation ◽  
Worst Case ◽  
Fault Trees ◽  
Starting Point ◽  
Failure Propagation ◽  
Event Trees

Safety engineering for complex systems is a very challenging task and the industry has a firm basis and trust on a set of established methods like the Probabilistic Risk Assessment (PRA). New methodologies for system engineering are being proposed by academia, some related to safety, but they have a limited chance for successful adoption by the safety industry unless they provide a clear connection and benefit in relation to the traditional methodologies. Model-Based System Engineering (MBSE) has produced multiple safety related applications. In past work system models were used to generate event trees, failure propagation scenarios and for early human reliability analyses. This paper extends previous work, on a high-level interdisciplinary system model for early defense in depth assessment, to support the automatic generation of fault tree statements for specific critical system components. These statements can then be combined into fault trees using software already utilized by the industry. The fault trees can then be linked to event trees in order to provide a more complete picture of an initiating event, the mitigating functions and critical components that are involved. The produced fault trees use a worst-case scenario approach by stating that if a dependency exists then the failure propagation is certain. Our proposed method doesn’t consider specific failure modes and related probabilities, a safety expert can use them as a starting point for further development. The methodology is demonstrated with a case study of a spent fuel pool cooling system of a nuclear plant.

The Case of Failure Analysis of the PCBA Wire Corrosion under High Reliability Requirements

2019 ◽  
Vol 2019 (1) ◽  
pp. 000369-000372
Author(s):  
Jie Zheng ◽  
Yabing Zou ◽  
Ying Yang ◽  
Jianghua Shen ◽  
Yingjie Zhang
Keyword(s):  
Cross Section ◽  
Ion Chromatography ◽  
Visual Inspection ◽  
High Reliability ◽  
Cleaning Process ◽  
Chromatography Analysis ◽  
Wave Soldering ◽  
Bromide Ion ◽  
Main Factors ◽  
Type Of Failure

Abstract The wire breakage of a no-cleaning process PCBA occurs at the beginning of the application. Through visual inspection, cross-section, SEM & EDS, and ion chromatography analysis, it was found that the high content of ions (bromide ion) on the surface of the solder source side caused corrosion and fracture of the conductors of wave soldering surface, this article also analyzes the source of bromide ion and conclude the main factors involved in this type of failure.

scholarly journals Avant-garde: An automated data-driven DIA data curation tool

2019 ◽  
Author(s):  
Alvaro Sebastian Vaca Jacome ◽  
Ryan Peckner ◽  
Nicholas Shulman ◽  
Karsten Krug ◽  
Katherine C. DeRuff ◽  
...  
Keyword(s):  
Visual Inspection ◽  
Limit Of Detection ◽  
Software Tools ◽  
Data Driven ◽  
False Discovery Rates ◽  
Avant Garde ◽  
Data Independent Acquisition ◽  
False Discovery ◽  
Peptide Signals ◽  
Discovery Rates

AbstractData-Independent Acquisition (DIA) is a technique that promises to comprehensively detect and quantify all peptides above an instrument’s limit of detection. Several software tools to analyze DIA data have been developed in recent years. However, several challenges still remain, like confidently identifying peptides, defining integration boundaries, dealing with interference for selected transitions, and scoring and filtering of peptide signals in order to control false discovery rates. In practice, a visual inspection of the signals is still required, which is impractical with large datasets. Avant-garde is a new tool to refine DIA (and PRM) by removing interfered transitions, adjusting integration boundaries and scoring peaks to control the FDR. Unlike other tools where MS runs are scored independently from each other, Avant-garde uses a novel data-driven scoring strategy. DIA signals are refined by learning from the data itself, using all measurements in all samples together to achieve the best optimization. We evaluated the performances of Avant-garde with a calibrated sample using spiked-in standards in a complex background, a phospho-enriched dataset (Abelin et al, 2016), and two complex hybrid proteome samples for benchmarking DIA software tools. The results clearly showed that Avant-garde is capable of improving the selectivity, accuracy, and reproducibility of the quantification results in very complex biological matrices. We have further shown that it can evaluate the suitability of a peak to be used for quantification reaching the same levels of selectivity, accuracy, and reproducibility obtained with manual validation.

scholarly journals Load-sharing Accounting Between the Renewable Communication Channels of the System of Three Iot-devices Connected by a Triangle

2020 ◽  
Author(s):  
Serhiy Shcherbovskykh ◽  
Tetyana Stefanovych
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Comparative Analysis ◽  
Fault Tree ◽  
Communication Channels ◽  
Load Sharing ◽  
Transition Diagram ◽  
Fault Trees ◽  
Iot Devices

The k-terminal dynamic fault trees for a system of three IoT-devices connected by a triangle are formed. Based on the fault tree a state and transition diagram is generated. This model can take into account adequately) load-sharing effects between renewable communication channels. Availability characteristics and failure causes characteristics are calculated based on Monte-Carlo simulation and comparative analysis for obtained results is done.

scholarly journals Fuzzy Fault Tree Reliability Analysis Based on Improved T–S Model with Application to NC Turret

2021 ◽  
Author(s):  
Yue Wu ◽  
Zhaojun Yang ◽  
Jili Wang ◽  
Wei Hu ◽  
N. Balakrishnan
Keyword(s):  
Preventive Maintenance ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Weak Links ◽  
Tree Model ◽  
Importance Index ◽  
Fuzzy Fault Tree Analysis ◽  
Importance Analysis ◽  
Mc Simulation ◽  
S Model

Abstract In Takagi and Sugeno (T–S) fuzzy fault tree analysis (FFTA), the construction of T-S fuzzy gates relies too much on expert experience, which will result in inevitable subjective errors. In order to overcome this disadvantage, a new method was proposed which combined importance index with T-S fuzzy fault tree model to evaluate reliability of the events. The importance index of components can be solved through Monte Carlo (MC) simulation. The proposed method is suitable for systems where exact information on the fault probabilities of the components and the magnitude of failure and effect on system are not available. The concept and calculation method of T-S probability importance was presented. Finally, the feasibility of the method is verified by analyzing the reliability of the sealing subsystem of the NC turret and the weak links of the system are obtained by the importance analysis, which will provide data for system fault diagnosis and preventive maintenance.

scholarly journals Qualitative Importance Measures of Systems Components – A New Approach and Its Applications

2016 ◽  
Vol 24 (4) ◽  
pp. 237-246 ◽  
Author(s):  
Leszek Chybowski ◽  
Katarzyna Gawdzińska ◽  
Bogusz Wiśnicki
Keyword(s):  
Fault Tree ◽  
Functional Model ◽  
Supply System ◽  
Engine Fuel ◽  
New Approach ◽  
Minimal Cut Set ◽  
Importance Analysis ◽  
Cut Set ◽  
Structural Measure ◽  
Main Engine

Abstract The paper presents an improved methodology of analysing the qualitative importance of components in the functional and reliability structures of the system. We present basic importance measures, i.e. the Birnbaum’s structural measure, the order of the smallest minimal cut-set, the repetition count of an i-th event in the Fault Tree and the streams measure. A subsystem of circulation pumps and fuel heaters in the main engine fuel supply system of a container vessel illustrates the qualitative importance analysis. We constructed a functional model and a Fault Tree which we analysed using qualitative measures. Additionally, we compared the calculated measures and introduced corrected measures as a tool for improving the analysis. We proposed scaled measures and a common measure taking into account the location of the component in the reliability and functional structures. Finally, we proposed an area where the measures could be applied.

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