scholarly journals A new heuristics for the event ordering in binary decision diagram applied in fault tree analysis

2019 ◽  
Vol 234 (2) ◽  
pp. 397-406
Author(s):  
Reni Banov ◽  
Zdenko Šimić ◽  
Davor Grgić
Keyword(s):  
Fault Tree ◽  
Fault Tree Analysis ◽  
Binary Decision Diagram ◽  
Tree Model ◽  
Binary Decision ◽  
Event Ordering ◽  
Tree Models ◽  
Ordering Schemes ◽  
Diagram Representation

Fault tree is a common approach in probabilistic risk assessment of complex engineering systems. Since their introduction, binary decision diagrams proved to be a valuable tool for complete quantification of hard fault tree models. As is known, the size of the binary decision diagram representation is mainly determined by the quality of the selected fault tree event ordering scheme. Finding the optimal event ordering for binary decision diagram representation is a computationally intractable problem, for which reason heuristic approaches are applied to find reasonable good ordering schemes. The existing method for finding optimal ordering schemes related to special types of fan-in 2 read-once formulas is employed in our research to develop a new heuristic for fault tree. Various fault tree simplification methods are used for the sake of reducing fault tree model discrepancy from fan-in 2 read-once formulas. The reduced fault tree is traversed in a depth-first manner, as for every gate, the best ordering scheme is chosen from selected sets of input permutations. The quality of the final event ordering scheme is compared to orderings produced with depth-first left most heuristic on a set of fault tree models addressed in the literature as well as on a set of our hard models. Our method proves to be a useful heuristic for finding good static event ordering, and it compares favourably to the known heuristic based on a depth-first left most assignment approach.

Design and Development of DeRisk: A Fault Tree Analysis Program Package

2018 ◽  
Author(s):  
Zhenxu Zhou ◽  
Hao Nie ◽  
Qin Zhang
Keyword(s):  
Fault Tree ◽  
Fault Tree Analysis ◽  
Good Choice ◽  
Binary Decision Diagram ◽  
Program Package ◽  
Analysis Program ◽  
Binary Decision ◽  
Tree Analysis ◽  
Input Module ◽  
Low Efficiency

Fault tree analysis (FTA) has been proven to be a very important tool and has been successfully applied to safety/reliability studies in nuclear, chemical, military, space industries/systems. Hitherto, several useful and popular FTA software/program packages have been developed, like CAFTA+, FAUNET, RiskSpectrum, SAPHIRE, RiskA etc. Minimum Cut Set (MCS) method is the most commonly used traditional FTA method. However, it suffers from low efficiency when solving remarkably large fault trees (FTs). To overcome the shortcomings of the traditional method, several new techniques are proposed such as Binary Decision Diagram (BDD), Zero-suppressed Binary Decision Diagram, (ZBDD) Petri Net (PN), Bayesian Network (BN) and Dynamic Uncertain Causality Graph (DUCG). DUCG is a newly presented Probabilistic Graphic Model to deal with systems with dynamics, uncertainties and logic cycles. DUCG is a good choice to analyze large FTs, in our previous papers, we have proved that any FT can be mapped into a DUCG graph and additional modeling and analytical power can be achieved. DeRisk is a DUCG embedded risk analysis program package written in C# for FTA and is designed as a powerful tool to assist reliability engineers. In this paper, the design schema and the main algorithms of DeRisk are introduced. DeRisk contains five parts: (1) A Graphical User Interface (GUI) Module which interacts with users; (2) A Preprocessing Module which preprocesses FTs (3) An Input Module which allows user to input necessary data by file or by command line; (4) A Calculation Module which offers qualitative/quantitative analysis; (5) An Output Module which outputs the results required by users. Some illustrative examples are used to verify the correctness and effectiveness of DeRisk.

Variable ordering schemes to apply to the binary decision diagram methodology for event tree sequences assessment

2008 ◽  
Vol 222 (1) ◽  
pp. 7-16 ◽  
Author(s):  
C Ibáñez-Llano ◽  
E Meléndez ◽  
Nieto F
Keyword(s):  
Fault Tree ◽  
Binary Decision Diagram ◽  
Event Tree ◽  
Final Size ◽  
Binary Decision ◽  
Reliability Models ◽  
Variable Ordering ◽  
Recent Approach ◽  
Event Trees ◽  
Ordering Schemes

Binary decision diagram (BDD) methodology is the most recent approach to improve Boolean reliability models assessment. The final size of the BDD, and therefore the ultimate benefits of this technique, are very sensitive to the initial variable ordering that has to be fixed prior to conversion. Several variable ordering strategies have been proposed in the literature, all of them focused on the treatment of single fault tree models. This paper proposes some extensions of existing variable ordering schemes for the case of combinations of non-disjoint fault trees, as is the case in quantifying sequences of event trees. These extensions work by combining ordering schemes applied to each fault tree, and exploring the cases where variables within the domains intersection are kept together or not. They have been specifically designed to be applied together with an incremental procedure to compute the BDD of the sequence accumulatively and to be used to quantify sequences of dynamic event trees. Preliminary results show the potential of this approach.

Efficient Ordering Heuristics in Binary Decision Diagram-based Fault Tree Analysis

2012 ◽  
Vol 29 (3) ◽  
pp. 307-315 ◽  
Author(s):  
Yuchang Mo ◽  
Farong Zhong ◽  
Huawen Liu ◽  
Quansheng Yang ◽  
Gang Cui
Keyword(s):  
Fault Tree ◽  
Fault Tree Analysis ◽  
Binary Decision Diagram ◽  
Binary Decision ◽  
Tree Analysis

scholarly journals Modelling and Resolution of Dynamic Reliability Problems by the Coupling of Simulink and the Stochastic Hybrid Fault Tree Object Oriented (SHyFTOO) Library

Information ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 283 ◽  
Author(s):  
Chiacchio ◽  
Aizpurua ◽  
Compagno ◽  
Khodayee ◽  
D’Urso
Keyword(s):  
Deterministic Model ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Object Oriented ◽  
Software Library ◽  
Tree Model ◽  
Dynamic Reliability ◽  
Simulink Model ◽  
Dynamic Fault Tree ◽  
Dependability Analysis

Dependability assessment is one of the most important activities for the analysis of complex systems. Classical analysis techniques of safety, risk, and dependability, like Fault Tree Analysis or Reliability Block Diagrams, are easy to implement, but they estimate inaccurate dependability results due to their simplified hypotheses that assume the components’ malfunctions to be independent from each other and from the system working conditions. Recent contributions within the umbrella of Dynamic Probabilistic Risk Assessment have shown the potential to improve the accuracy of classical dependability analysis methods. Among them, Stochastic Hybrid Fault Tree Automaton (SHyFTA) is a promising methodology because it can combine a Dynamic Fault Tree model with the physics-based deterministic model of a system process, and it can generate dependability metrics along with performance indicators of the physical variables. This paper presents the Stochastic Hybrid Fault Tree Object Oriented (SHyFTOO), a Matlab® software library for the modelling and the resolution of a SHyFTA model. One of the novel features discussed in this contribution is the ease of coupling with a Matlab® Simulink model that facilitates the design of complex system dynamics. To demonstrate the utilization of this software library and the augmented capability of generating further dependability indicators, three different case studies are discussed and solved with a thorough description for the implementation of the corresponding SHyFTA models.

The Application of Fault Tree Analysis in the Safety Performance of Cutter Suction Dredger

2013 ◽  
Vol 405-408 ◽  
pp. 3298-3301
Author(s):  
Yu Gang Zhou ◽  
Huan Min Xu
Keyword(s):  
Failure Probability ◽  
Land Reclamation ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Production Capacity ◽  
Product Configuration ◽  
Tree Model ◽  
Tree Analysis ◽  
Basic Probability ◽  
Key Events

Cutter suction dredgers (CSD) play a major part in the field of dredging engineering in harbors, fairways, and land reclamation. CSD can continuously mine and transport the slop with good quality while CSD can tackle many types of soil. However, even a component failure, which is connected with parts and components of CSD, can result in no working. Thus, it affects the production capacity and efficiency of dredgers seriously. It is necessary to analyze the failure probability of CSD. The method of Fault Tree Analysis (FTA) is applied to analyze the failure probability of CSD. The method uses logical reasoning and builds a fault tree model by analyzing the relationship between the basic, intermediate and top events. Based on fault tree model of a variety of events " and " " or " relationship, we can obtain minimal cut sets of that cause the event to failure. Then, get the basic probability of the event. Finally, we can calculate the probability of the top events. Under experiments, the FTA method can accurately calculate the failure probability of CSD, and deduce in reverse order the key events that cause the top event. The study on the key events can reduce the failure probability of CSD, enhance its reliability and safety, and improve the efficiency and productivity indirectly. It will also lay a foundation for product configuration optimization.

Research of the Node Ordering Technique According to the Shortest Fault Tree

2017 ◽  
Author(s):  
Guofeng Tang ◽  
Jingyu Zhang ◽  
Wei Gao ◽  
Qinfang Zhang
Keyword(s):  
Safety Assessment ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Binary Decision ◽  
Tree Analysis ◽  
Advanced Method ◽  
Probabilistic Safety Assessment ◽  
The Core ◽  
Minimal Cut Sets ◽  
Variable Ordering

Zero-suppressed Binary Decision Diagram (ZBDD) algorithm is an advanced method in fault tree analysis, which is developing quickly in recent years and being used in the development of the Probabilistic Safety Assessment (PSA) Quantification Engine. This algorithm converts a fault tree to a ZBDD structure, solves the minimal cut sets and calculates the top node unavailability. The ordering of the basic events and logical gates is the core technique of the ZBDD algorithm, which determines the efficiency of the ZBDD conversion and the size of the ZBDD structure. A variable ordering method based on the structure of the fault tree is developed in this paper, which gives a better basic events order by compressing the fault tree; meanwhile, the method offers a logical gates order. The nodes order derived from this method can accelerate the ZBDD conversion obviously.

Sign in / Sign up

Export Citation Format

Share Document