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All Outputs (17)

Fault Tree Analysis Including Component Dependencies (2023)
Journal Article
Tolo, S., & Andrews, J. (2023). Fault Tree Analysis Including Component Dependencies. IEEE Transactions on Reliability, https://doi.org/10.1109/tr.2023.3264943

Fault Tree analysis is not only the most common technique used in engineering practice for the estimation of system reliability, but is also a key tool shared between designers, analysts and regulators for safe operation and licensing purposes. In sp... Read More about Fault Tree Analysis Including Component Dependencies.

Dynamic safety and degradation analysis of an aircraft internal air system (2023)
Presentation / Conference
Tolo, S., Andrews, J., Thatcher, I., & Stamp, D. (2023, April). Dynamic safety and degradation analysis of an aircraft internal air system. Presented at 62nd ESReDA Seminar, University of Twente, the Netherlands

The modelling of the dynamic behaviour of engineering systems offers an invaluable insight in the evolution of degradation and response of systems to failure and represents an essential step to lay the basis for resilience analysis. While traditional... Read More about Dynamic safety and degradation analysis of an aircraft internal air system.

The Dynamic and Dependent Tree Theory (D2T2 ) methodology Developed for Fault Tree Analysis (2023)
Presentation / Conference
Andrews, J., & Tolo, S. (2023, April). The Dynamic and Dependent Tree Theory (D2T2 ) methodology Developed for Fault Tree Analysis. Presented at 62nd ESReDA Seminar, University of Twente, the Netherlands

Fault Tree Analysis (FTA) has its origins back in the 1960’s with the mathematical framework, known as Kinetic Tree Theory (KTT) added at the end of the decade by Vesely. In KTT the analysis of the fault tree is performed in two stages. The first sta... Read More about The Dynamic and Dependent Tree Theory (D2T2 ) methodology Developed for Fault Tree Analysis.

Dependent and Dynamic Tree Theory (D2T2 ) for Event Tree Applications (2023)
Presentation / Conference
Tolo, S., & Andrews, J. (2023, April). Dependent and Dynamic Tree Theory (D2T2 ) for Event Tree Applications. Presented at 62nd ESReDA Seminar, University of Twente, the Netherlands

The demand for innovative and effective computational tools able to improve the accuracy of present modelling methodologies has been fuelled by the ever-increasing complexity of engineering systems. In spite of their shortcomings, such as their inabi... Read More about Dependent and Dynamic Tree Theory (D2T2 ) for Event Tree Applications.

Dynamic and dependent tree theory (D2T2): A framework for the analysis of fault trees with dependent basic events (2022)
Journal Article
Andrews, J., & Tolo, S. (2023). Dynamic and dependent tree theory (D2T2): A framework for the analysis of fault trees with dependent basic events. Reliability Engineering and System Safety, 230, Article 108959. https://doi.org/10.1016/j.ress.2022.108959

Fault tree analysis remains the most commonly employed method, particularly in the safety critical industries, to predict the probability or frequency of system failures. Whilst it has its origins back in the 1960s, the assumptions employed in the ma... Read More about Dynamic and dependent tree theory (D2T2): A framework for the analysis of fault trees with dependent basic events.

An integrated modelling framework for complex systems safety analysis (2022)
Journal Article
Tolo, S., & Andrews, J. (2022). An integrated modelling framework for complex systems safety analysis. Quality and Reliability Engineering International, 38(8), 4330-4350. https://doi.org/10.1002/qre.3212

The ever-increasing complexity of engineering systems has fuelled the need for novel and efficient computational tools able to enhance the accuracy of current modelling strategies for industrial systems. Indeed, traditional Fault and Event Tree techn... Read More about An integrated modelling framework for complex systems safety analysis.

Fault Tree analysis including component dependencies (2022)
Conference Proceeding
Tolo, S., & Andrews, J. (2022). Fault Tree analysis including component dependencies. In M. C. Leva, E. Patelli, L. Podofillini, & S. Wilson (Eds.), Book of Extended Abstracts for the 32nd European Safety and Reliability Conference (133-134). https://doi.org/10.1109/TR.2023.3264943

The inability of commonly used risk assessment methodologies to model component dependency is often recognised to be a barrier towards more realistic modelling of systems complexity. This is a significant limitation associated with widely adopted tec... Read More about Fault Tree analysis including component dependencies.

A Petri Net approach to the Risk Analysis of Jet Engines (2022)
Conference Proceeding
Tolo, S., Andrews, J., Thatcher, I., & Stamp, D. (2022). A Petri Net approach to the Risk Analysis of Jet Engines. In M. Chiara Leva, E. Patelli, L. Podofillini, & S. Wilson (Eds.), Book of Extended Abstracts for the 32nd European Safety and Reliability Conference (137-138)

Traditional risk analysis techniques such as Fault Trees and Event Trees fail to model complex aspects of systems behaviour such as components dependencies, degradation, limiting their capability of representing modern engineering systems. This is al... Read More about A Petri Net approach to the Risk Analysis of Jet Engines.

An Integrated Modelling Framework for Complex Systems Safety Analysis: Case-Studies (2022)
Conference Proceeding
Tolo, S., & Andrews, J. (2022). An Integrated Modelling Framework for Complex Systems Safety Analysis: Case-Studies. In M. C. Leva, E. Patelli, L. Podofillini, & S. Wilson (Eds.), Book of Extended Abstracts for the 32nd European Safety and Reliability Conference (135-136)

The ever-increasing complexity of engineering systems has fuelled the need for novel and efficient computational tools able to enhance the accuracy of current modelling strategies for industrial systems. Indeed, traditional Fault and Event Tree techn... Read More about An Integrated Modelling Framework for Complex Systems Safety Analysis: Case-Studies.

Dynamic and Dependent Tree Theory (D 2 T 2 ): A Fault Tree Analysis Framework (2022)
Conference Proceeding
Andrews, J., & Tolo, S. (2022). Dynamic and Dependent Tree Theory (D 2 T 2 ): A Fault Tree Analysis Framework. In M. Chiara Leva, E. Patelli, L. Podofillini, & S. Wilson (Eds.), Book of Extended Abstracts for the 32nd European Safety and Reliability Conference (139-140)

A modelling framework, known as Dynamic and Dependent Tree Theory, is provided which overcomes restrictions in the Kinetic Tree Theory developed in the 1970s for the analysis of fault trees. Kinetic Tree Theory assumes basic events to be independent... Read More about Dynamic and Dependent Tree Theory (D 2 T 2 ): A Fault Tree Analysis Framework.

A Petri Net Methodology for Modeling the Resilience of Nuclear Power Plants (2021)
Conference Proceeding
Yan, R., Dunnett, S., Tolo, S., & Andrews, J. (2021). A Petri Net Methodology for Modeling the Resilience of Nuclear Power Plants. In B. Castanier, M. Cepin, D. Bigaud, & C. Berenguer (Eds.), In Proceedings of the 31st European Safety and Reliability Conference (ESREL 2021) (2426-2432). https://doi.org/10.3850/978-981-18-2016-8_109-cd

In the paper, a novel Petri Net (PN) method for assessing the resilience of nuclear reactors is presented. The PN model constructed aims to simulate the failure of the subsystems in a reactor caused by either natural degradation or external disruptiv... Read More about A Petri Net Methodology for Modeling the Resilience of Nuclear Power Plants.

A Modelling Framework for Dynamic Safety Assessment (2021)
Conference Proceeding
Tolo, S., Yan, R., Dunnett, S., & Andrews, J. (2021). A Modelling Framework for Dynamic Safety Assessment. In B. Castanier, M. Cepin, D. Bigaud, & C. Berenguer (Eds.), Proceedings of the 31st European Safety and Reliability Conference (ESREL 2021) (2434-2440). https://doi.org/10.3850/978-981-18-2016-8_163-cd

The concept of resilience is progressively making its way into the design, operation and management practice of complex engineering systems. The core of such trend lies with the integration of failure mechanisms in the modelling of systems since the... Read More about A Modelling Framework for Dynamic Safety Assessment.

Evolved Methods for Risk Assessment (2021)
Conference Proceeding
Jackson, A., Tolo, S., & Andrews, J. (2021). Evolved Methods for Risk Assessment. In B. Castanier, M. Cepin, D. Bigaud, & C. Berenguer (Eds.), Proceedings of the 31st European Safety and Reliability Conference (ESREL 2021) (217-224). https://doi.org/10.3850/978-981-18-2016-8_194-cd

The foundations of risk assessment tools such as fault tree analysis and event tree analysis were established in the 1970s. Since then, research has made considerable advances in the capabilities of analytical techniques applicable to safety critical... Read More about Evolved Methods for Risk Assessment.

Resilience in the context of Nuclear safety engineering (2020)
Conference Proceeding
Yan, R., Tolo, S., Dunnett, S., Andrews, J., & Patelli, E. (2020). Resilience in the context of Nuclear safety engineering

The safety and reliability of critical infrastructures is a key challenge in modern societies. This is all the more true when referring to the nuclear power industry, due to the rigid safety requirements on the one hand and the growing complexity of... Read More about Resilience in the context of Nuclear safety engineering.

Pseudo Credal Networks for Inference With Probability Intervals (2019)
Journal Article
Estrada-Lugo, H. D., Tolo, S., de Angelis, M., & Patelli, E. (2019). Pseudo Credal Networks for Inference With Probability Intervals. ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering, 5(4), Article RISK-18-1097. https://doi.org/10.1115/1.4044239

The computation of the inference corresponds to an NP-hard problem even for a single connected credal network. The novel concept of pseudo networks is proposed as an alternative to reduce the computational cost of probabilistic inference in credal ne... Read More about Pseudo Credal Networks for Inference With Probability Intervals.