Computer Aided Fault Tree Analysis Research Articles

Method of Computer-Aided Fault Tree Analysis for High-Reliable and Safety Design

Fault tree analysis (FTA) is a method of analyzing and visualizing the causes of a fault using a fault tree diagram (FT diagram), which has a tree structure with logical steps. Design engineers developing a new product generally use FTA to analyze many fault events, calculate their probability, and include redundancy systems in the design process. Furthermore, FTA has been used to analyze problems with products and to prevent the occurrence of problems in the design phase. In particular, it is necessary for design engineers to analyze the events after a failure to determine the root causes of the failure of the redundancy systems. However, it is not easy for design engineers to produce an accurate FT diagram in the actual design process. We have developed a computer-aided knowledge management system for creating FT diagrams (FTAid) as part of a collaborative group (The University of Tokyo, National Institute of Advanced Industrial Science and Technology (AIST), and Jatco Ltd.). This system has been verified by the design engineers of Jatco Ltd. in actual product development. We report its effectiveness for predicting mechanical, electrical, and heat transfer failure, the verification of the system, and its validation in an actual design process. We conclude that the system can help design engineers to effectively and efficiently create FT diagrams in reliability engineering, although some existing ability in FTA and engineering is required. We also describe some outstanding issues regarding the improvement of FTAid, engineering education, and ensuring reliability.

3302 高信頼性設計のためのFTA支援手法 : 設計で用いる故障モードでのシステム有効性検証(OS4-1 知識マネジメント・情報共有1,OS4 知識マネジメント・情報共有)

3302 高信頼性設計のためのFTA支援手法 : 設計で用いる故障モードでのシステム有効性検証(OS4-1 知識マネジメント・情報共有1,OS4 知識マネジメント・情報共有)

The Computer Aided Fault Tree Modeling and Analysis of the Refrigerator Evaporator Failure

The paper analyzes the various factors that cause failure of refrigerator evaporator. The refrigerator evaporator failure spectrum is constructed through qualitative analysis of the fault tree system after building a corresponding fault tree system. There is an analysis procedure of fault tree system based on computer aided fault tree analysis system (CAFTA).

Method of Computer-Aided FTA (Fault Tree Analysis) in Reliability Design and Development; Using Knowledge Management Based on Quantity Dimension Indexing and Block Diagram

Method of Computer-Aided FTA (Fault Tree Analysis) in Reliability Design and Development; Using Knowledge Management Based on Quantity Dimension Indexing and Block Diagram

J112021 高信頼性設計のためのFault Tree Analysis 支援システムの開発

J112021 高信頼性設計のためのFault Tree Analysis 支援システムの開発

3210 高信頼性設計のためのFault Tree Analysis支援システムの開発 : ブロック図からFT形式への変換(OS8-2 知識マネジメント・情報共有)

3210 高信頼性設計のためのFault Tree Analysis支援システムの開発 : ブロック図からFT形式への変換(OS8-2 知識マネジメント・情報共有)

2211 高信頼性設計のためのFault Tree Analysis支援システムの開発 : 設計現場でのFault Tree Analysis支援システムの効果検証と実用性評価(OS8-2 知識マネジメント・情報共有II,OS8 知識マネジメント・情報共有)

2211 高信頼性設計のためのFault Tree Analysis支援システムの開発 : 設計現場でのFault Tree Analysis支援システムの効果検証と実用性評価(OS8-2 知識マネジメント・情報共有II,OS8 知識マネジメント・情報共有)

2210 高信頼性設計のためのFault Tree Analysis支援システムの開発 : MZ Platformを用いた研究成果活用基盤としての実装(OS8-2 知識マネジメント・情報共有II,OS8 知識マネジメント・情報共有)

2210 高信頼性設計のためのFault Tree Analysis支援システムの開発 : MZ Platformを用いた研究成果活用基盤としての実装(OS8-2 知識マネジメント・情報共有II,OS8 知識マネジメント・情報共有)

2209 高信頼性設計のためのFault Tree Analysis支援システムの開発 : 物理量次元インデクシングによるFTAの知識マネジメント(OS8-2 知識マネジメント・情報共有II,OS8 知識マネジメント・情報共有)

2209 高信頼性設計のためのFault Tree Analysis支援システムの開発 : 物理量次元インデクシングによるFTAの知識マネジメント(OS8-2 知識マネジメント・情報共有II,OS8 知識マネジメント・情報共有)

Methodology for computer aided fuzzy fault tree analysis

Probabilistic risk assessment (PRA) is a comprehensive, structured and logical analysis method aimed at identifying and assessing risks of complex process systems. PRA uses fault tree analysis (FTA) as a tool to identify basic causes leading to an undesired event, to represent logical dependency of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event. To conduct a quantitative fault tree analysis, one needs a fault tree along with failure data of the basic events (components). Sometimes it is difficult to have an exact estimation of the failure rate of individual components or the probability of occurrence of undesired events due to a lack of sufficient data. Further, due to imprecision in basic failure data, the overall result may be questionable. To avoid such conditions, a fuzzy approach may be used with the FTA technique. This reduces the ambiguity and imprecision arising out of subjectivity of the data. This paper presents a methodology for a fuzzy based computer-aided fault tree analysis tool. The methodology is developed using a systematic approach of fault tree development, minimal cut sets determination and probability analysis. Further, it uses static and dynamic structuring and modeling, fuzzy based probability analysis and sensitivity analysis. This paper also illustrates with a case study the use of a fuzzy weighted index and cutsets importance measure in sensitivity analysis (for system probabilistic risk analysis) and design modification.

Methodology for Computer-Aided Fault Tree Analysis

Fault tree analysis is a systematic, deductive and probabilistic risk assessment tool which elucidates the causal relations leading to a given undesired event. Quantitative fault tree (failure) analysis requires a fault tree and failure data of basic events. Development of a fault tree and subsequent analysis require a great deal of expertise, which may not be available all the time. Computer-aided fault tree analysis is an easy-to-use approach, which not only provides reliable results but also facilitates the validation and repeatability of the analysis. This enhances the overall results of the fault tree analysis and quantitative risk analysis. This paper presents a revised methodology for computer-aided fault tree analysis. The methodology includes fault tree development, minimal cutsets determination, cutsets optimization and probability analysis. The methodology uses advanced concepts of fault tree development and static and dynamic modularizing for complex and large fault trees. Furthermore, it enables sensitivity analysis of the system for design modification and risk-based decision making. Application of the proposed methodology to a process system is also discussed in the paper.

Classification of fault trees and algorithms of fault tree analysis

A new classification of fault trees is proposed, and the relationship between the new and old classifications is discussed. The new classification is illustrated with an example, and the limitation of the well-known simple prime implicant algorithm, which can work on fault trees, is shown. Thus a general unified algorithm for computer-aided fault tree analysis is presented.

Development of SUPKIT-II: Computer Aided Fault Tree Analysis System

A computer aided reliability analysis system, in which an interactive graphic terminal can be used, to construct, modify, analyze, and store fault trees is developed. The system, SUPKIT-n, a computer aided fault tree analysis system has functions for fault tree automated construction (PREP) and fault tree graphics (GRAPH). The former automatically generates a fault tree by a hierachical structure based on system configuration and specifications, and/or from failure information, while the latter indicates, modifies, and evaluates the fault tree through CAD/CAM terminals. Therefore, PREP decreases man-hours and mistake occurrences in constructing fault trees and GRAPH enables users to evaluate system reliability and to compare system design plans easily and quickly.

Development of SUPKIT-II: Computer aided fault tree analysis system.

A computer aided reliability analysis system, in which an interactive graphic terminal can be used, to construct, modify, analyze, and store fault trees is developed. The system, SUPKIT-n, a computer aided fault tree analysis system has functions for fault tree automated construction (PREP) and fault tree graphics (GRAPH). The former automatically generates a fault tree by a hierachical structure based on system configuration and specifications, and/or from failure information, while the latter indicates, modifies, and evaluates the fault tree through CAD/CAM terminals. Therefore, PREP decreases man-hours and mistake occurrences in constructing fault trees and GRAPH enables users to evaluate system reliability and to compare system design plans easily and quickly.