Dependability Evaluation with Dynamic Reliability Block Diagrams and Dynamic Fault Trees

2009 ◽  
Vol 6 (1) ◽  
pp. 4-17 ◽  
Author(s):  
S. Distefano ◽  
A. Puliafito
Keyword(s):  
Fault Trees ◽  
Dynamic Reliability ◽  
Dependability Evaluation ◽  
Reliability Block Diagrams

scholarly journals The Mercury Environment: A Modeling Tool for Performance and Dependability Evaluation

2021 ◽  
Author(s):  
Thiago Pinheiro ◽  
Danilo Oliveira ◽  
Rubens Matos ◽  
Bruno Silva ◽  
Paulo Pereira ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Markov Chains ◽  
Mathematical Models ◽  
Discrete Time ◽  
Stochastic Petri Nets ◽  
System Behavior ◽  
Fault Trees ◽  
Flow Models ◽  
Dependability Evaluation ◽  
Reliability Block Diagrams

It is important to be able to judge the performance or dependability metrics of a system and often we do so by using abstract models even when the system is in the conceptual phase. Evaluating a system by performing measurements can have a high temporal and/or financial cost, which may not be feasible. Mathematical models can provide estimates about system behavior and we need tools supporting different types of formalisms in order to compute desired metrics. The Mercury tool enables a range of models to be created and evaluated for supporting performance and dependability evaluations, such as reliability block diagrams (RBDs), dynamic RBDs (DRBDs), fault trees (FTs), stochastic Petri nets (SPNs), continuous and discrete-time Markov chains (CTMCs and DTMCs), as well as energy flow models (EFMs). In this paper, we introduce recent enhancements to Mercury, namely new SPN simulators, support to prioritized timed transitions, sensitivity analysis evaluation, several improvements to the usability of the tool, and support to DTMC and FT formalisms.

Drbd: Dynamic Reliability Block Diagrams for System Reliability Modelling

2009 ◽  
Vol 31 (2) ◽  
pp. 132-141 ◽  
Author(s):  
H. Xu ◽  
L. Xing ◽  
R. Robidoux
Keyword(s):  
System Reliability ◽  
Dynamic Reliability ◽  
Reliability Modelling ◽  
Reliability Block Diagrams

scholarly journals Decision Diagram Algorithms to Extract Minimal Cutsets of Finite Degradation Models

Information ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 368 ◽  
Author(s):  
Antoine Rauzy ◽  
Yang
Keyword(s):  
Oil And Gas ◽  
Decomposition Theorem ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Fault Trees ◽  
Attack Trees ◽  
Degradation Models ◽  
Reliability Block Diagrams ◽  
And Performance ◽  
The One

In this article, we propose decision diagram algorithms to extract minimal cutsets of finite degradation models. Finite degradation models generalize and unify combinatorial models used to support probabilistic risk, reliability and safety analyses (fault trees, attack trees, reliability block diagrams…). They formalize a key idea underlying all risk assessment methods: states of the models represent levels of degradation of the system under study. Although these states cannot be totally ordered, they have a rich algebraic structure that can be exploited to extract minimal cutsets of models, which represent the most relevant scenarios of failure. The notion of minimal cutsets we introduce here generalizes the one defined for fault trees. We show how algorithms used to calculate minimal cutsets can be lifted up to finite degradation models, thanks to a generic decomposition theorem and an extension of the binary decision diagrams technology. We discuss the implementation and performance issues. Finally, we illustrate the interest of the proposed technology by means of the use case stemmed from the oil and gas industry.

Information System Availability

2017 ◽  
pp. 1-33
Keyword(s):  
Information System ◽  
Information Systems ◽  
Markov Chains ◽  
Short Introduction ◽  
System Availability ◽  
Fault Trees ◽  
Reliability Block Diagrams ◽  
Availability Modeling

In order to provide better understanding of the availability concept, it is necessary to define and review the terms that shape a framework for information systems availability. This section introduces the concept of availability and the three terms that are most associated with the concept of availability, namely: dependability, reliability and maintainability. A short introduction to availability modeling is also presented in this section by explaining three most widely used methods: Reliability Block Diagrams, Fault Trees Diagrams, and Markov Chains.

RELIABILITY EVALUATION OF WSN WITH DYNAMIC-DEPENDENT NODES

2011 ◽  
Vol 18 (06) ◽  
pp. 515-530 ◽  
Author(s):  
SALVATORE DISTEFANO
Keyword(s):  
Power Management ◽  
Markov Models ◽  
Geographical Area ◽  
Sensor Nodes ◽  
Dynamic Reliability ◽  
Node Level ◽  
Autonomous Sensor ◽  
Network Topologies ◽  
Reliability Block Diagrams ◽  
Standby Power

A wireless sensor network (WSN) is a distributed system composed of autonomous sensor nodes wireless connected and randomly scattered into a geographical area to cooperatively monitor physical or environmental conditions. Adequate techniques and strategies are required to manage a WSN in order it works properly, mainly focusing on its reliability. From the system reliability perspective, it is important to take into account that WSN nodes are usually battery-powered and the WSN reliability strongly depends on the power management at node level. Since standby power management policies are often applied at node level and, moreover, interferences among nodes may arise, a WSN can be considered as a system affected by dynamic-dependent behaviors among its components and therefore, the dynamic reliability approach can be applied. Static-structural interactions are specified by the WSN topology. Active–sleep standby policies and interferences due to wireless communications can be instead considered as dynamic aspects. Thus, in order to represent and to evaluate the WSN reliability dynamic reliability block diagrams are used in this paper. The proposed technique allows to overcome the limits of Markov models when considering nonlinear discharge processes, since such models cannot adequately represent the node aging process. In order to demonstrate the effectiveness of the DRBD technique in this context, we investigate some specific WSN network topologies, providing guidelines for their representation and evaluation.

Reliability Assessment of Control Systems

2011 ◽  
Vol 467-469 ◽  
pp. 174-180
Author(s):  
Salvatore Distefano
Keyword(s):  
Control System ◽  
Control Systems ◽  
Reliability Assessment ◽  
Critical Systems ◽  
Monitoring And Control ◽  
Dynamic Reliability ◽  
Reliability Block Diagrams ◽  
Safety Critical Systems ◽  
The Right ◽  
And Control

Actually modern systems have to ensure higher and higher operating standards, thus including monitoring and control subsystems for their achievement. In safety critical systems control is a crucial task in order to satisfy strict reliability requirements. But it is also necessary that the control system is itself reliable. As a consequence, adequate techniques are necessary in order to perform reliability evaluation of both the controlled and the control systems. Techniques that therefore should avoid over-simplistic assumptions and/or approximations that, for example, are usually introduced when dependencies, interferences and other dynamic reliability aspects are not taken into the right consideration. In this paper, a technique for carefully evaluating the reliability of such systems, also considering dynamic aspects and behaviors, is proposed. Firstly the technique is detailed through the specification of the dynamic reliability block diagrams notation, and therefore in order to demonstrate its effectiveness, it is applied to an example of a computing-based control system taken from literature, thus providing guidelines for the reliability representation and evaluation through DRBD.

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