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

Abstract

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.

Fmdtools

“…fmdtools has additionally since expanded in scope to include not just fault propagation tools but the necessary analysis and visualization tools needed to interpret Toolkit Causality Representation Model Format(s) Availability Use in design HiP-Hops (Papadopoulos & McDermid, 1999) Dynamic simulation with failure logic Simulink, Simula-tionX, AADL, etc. Commercial Functional Hazard Assessment, Design Optimization (Papadopoulos et al, 2011) Rodon (Bunus et al, 2009) Behavioral constraint network with failure logic Modelica-like Rodelica model Commercial Model-based engineering process (Lunde et al, 2006) Modelica fault libraries (van der Linden, 2014;Minhas et al, 2014;Gundermann et al, 2019) Undirected behavioral/failure logic Modelica Open Source Design exploration (Lattmann et al, 2014) OpenErrorPro (Morozov et al, 2019) Probabilistic markov chain Simulink, Stateflow, UML, SysML, AADL Open Source Model-based reliable system design (Morozov et al, 2018) SHyFTOO (Chiacchio et al, 2020) Dynamic simulation with probabilistic hybrid fault tree Simulink, MAT-LAB code Open Source Model-based design (Chiacchio et al, 2019) OpenCossan (Patelli et al, 2018) Probabalistic semi-markov transitions and/or external simulation…”

“…Resilience, the ability to prevent and mitigate hazards, is a key consideration in the design of complex engineered systems (Cottam et al, 2019;Yodo & Wang, 2016a). In the aerospace industry, for example, it is important that aircraft adapt and recover from hazards (Choi, Atkins, & Yi, 2010), airports reconfigure runways in the event of damage (Faturechi, Levenberg, & Miller-Hooks, 2014), and supply chains that mitigate disruptions (Treuner, Hübner, Baur, & Wagner, 2014). Because resilience factors heavily into the risk, safety, and functional reliability of a system, it is important to proactively consider resilience in the early design phase, when there is the most freedom to consider alternatives and allocate PHM features (Yodo & Wang, 2016b;Youn, Hu, & Wang, 2011).…”

A Novel Approach Based on Stochastic Hybrid Fault Tree to Compare Alternative Flare Gas Recovery Systems

“…This modelling represents a second important novelty with respect to the state of the art because the results obtained prove that the hybrid model gives evidences and insights that would not emerge using Dynamic Fault Tree. Summarizing, the main objectives of this paper are to: -Discuss two different design solutions for improving the gas flaring process of the plant of South Pars; -Model the corresponding Dynamic and Hybrid Fault Trees of the two different design solutions; -Perform a Monte Carlo simulation of the two models by using a Matlab®-based software library [47]; -Analyse and compare the difference between the DFT and the HDFT results, to demonstrate that the latter provide further information for determining the most suitable design solution. This paper is organized as follows.…”

Importance Analysis of Components of a Multi-Operational-State Power System Using Fault Tree Models

“…One method for modeling the system reliability structure is the fault tree analysis. The structure of time-variant systems can be modeled using dynamic fault trees and suitable additional functional blocks (gates) that describe complex logical and time-related relationships in the analyzed system [29][30][31]. Often, however, due to the need to simplify the model, it is necessary to use static fault trees, that is, trees using basic static logical gates to describe the relationship between events in a system [32][33][34][35].…”