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Calculation of the System Unavailability Measures of Component Importance Using the D2T2 Methodology of Fault Tree Analysis (2024)
Journal Article
Andrews, J., & Lunt, S. (2024). Calculation of the System Unavailability Measures of Component Importance Using the D2T2 Methodology of Fault Tree Analysis. Mathematics, 12(2), Article 292. https://doi.org/10.3390/math12020292

A recent development in Fault Tree Analysis (FTA), known as Dynamic and Dependent Tree Theory (D2T2), accounts for dependencies between the basic events, making FTA more powerful. The method uses an integrated combination of Binary Decision Diagrams... Read More about Calculation of the System Unavailability Measures of Component Importance Using the D2T2 Methodology of Fault Tree Analysis.

Analysing the impact of local factors on the life cycle of metallic bridge girders (2023)
Presentation / Conference Contribution
Calvert, G., Hamer, M., Neves, L., & Andrews, J. (2023). Analysing the impact of local factors on the life cycle of metallic bridge girders. In F. Biondini, & D. M. Frangopol (Eds.), Life-Cycle of Structures and Infrastructure Systems: PROCEEDINGS OF THE EIGHTH INTERNATIONAL SYMPOSIUM ON LIFE-CYCLE CIVIL ENGINEERING (IALCCE 2023), 2-6 JULY, 2023, POLITECNICO DI MILANO, MILAN, ITALY

A fundamental component of a life cycle analysis of a bridge is the modelling of asset condition post-construction. To enhance the accuracy of bridge deterioration models, several studies have calibrated models based on cohorts that incorporate struc... Read More about Analysing the impact of local factors on the life cycle of metallic bridge girders.

Fault Tree Analysis Including Component Dependencies (2023)
Journal Article
Tolo, S., & Andrews, J. (2024). Fault Tree Analysis Including Component Dependencies. IEEE Transactions on Reliability, 73(1), 413-421. 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.

Next Generation Prediction Methodologies and Tools for System Safety Analysis (NxGen) – A Project Overview (2023)
Presentation / Conference Contribution
Sanderson, K., & Andrews, J. (2023, April). Next Generation Prediction Methodologies and Tools for System Safety Analysis (NxGen) – A Project Overview. Presented at 62nd ESReDA Seminar, University of Twente, the Netherlands

Modern engineering systems are rapidly increasing in size and complexity, posing greater safety and risk management challenges than ever before. In addition to this, the threats to these engineering systems are constantly changing and new hazards eme... Read More about Next Generation Prediction Methodologies and Tools for System Safety Analysis (NxGen) – A Project Overview.

The Dynamic and Dependent Tree Theory (D2T2 ) methodology Developed for Fault Tree Analysis (2023)
Presentation / Conference Contribution
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.

Dynamic safety and degradation analysis of an aircraft internal air system (2023)
Presentation / Conference Contribution
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.

Dependent and Dynamic Tree Theory (D2T2 ) for Event Tree Applications (2023)
Presentation / Conference Contribution
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.

A Petri net model-based resilience analysis of nuclear power plants under the threat of natural hazards (2022)
Journal Article
Yan, R., Dunnett, S., & Andrews, J. (2023). A Petri net model-based resilience analysis of nuclear power plants under the threat of natural hazards. Reliability Engineering and System Safety, 230, Article 108979. https://doi.org/10.1016/j.ress.2022.108979

Due to global climate change, nuclear power plants are increasingly exposed to the threats of extreme natural disasters. In this paper, a resilience engineering approach is applied to tackle all aspects of nuclear safety, spanning from design, operat... Read More about A Petri net model-based resilience analysis of nuclear power plants under the threat of natural hazards.

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.

Optimisation of nuclear reactor primary coolant design and maintenance parameters (2022)
Journal Article
Wootton, M. J., Zhou, Y., Andrews, J. D., Smith, R., Arul, A. J., Vinod, G., …Garg, V. (2024). Optimisation of nuclear reactor primary coolant design and maintenance parameters. Applied Stochastic Models in Business and Industry, 40(3), 725-745. https://doi.org/10.1002/asmb.2722

An optimisation methodology is presented using the primary coolant circulation system of a nuclear reactor as its case study, the purpose of which is to find combinations of selected design and maintenance parameters to maximise the reactor safety an... Read More about Optimisation of nuclear reactor primary coolant design and maintenance parameters.

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.

Dynamic and Dependent Tree Theory (D 2 T 2 ): A Fault Tree Analysis Framework (2022)
Presentation / Conference Contribution
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.

An Integrated Modelling Framework for Complex Systems Safety Analysis: Case-Studies (2022)
Presentation / Conference Contribution
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.

A Petri Net approach to the Risk Analysis of Jet Engines (2022)
Presentation / Conference Contribution
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.

Fault Tree analysis including component dependencies (2022)
Presentation / Conference Contribution
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 asset management framework for railway switches and crossings (2022)
Journal Article
Litherland, J., & Andrews, J. (2022). A Petri net asset management framework for railway switches and crossings. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, https://doi.org/10.1177/09544097221110970

Switches and Crossings (S&C) are a fundamental part of any railway network, they allow trains to switch between tracks and to cross over other tracks. They consist of various electrical and mechanical components to which there is a substantial mainte... Read More about A Petri net asset management framework for railway switches and crossings.

Reduction of Petri net maintenance modeling complexity via Approximate Bayesian Computation (2022)
Journal Article
Chiachío, M., Saleh, A., Naybour, S., Chiachío, J., & Andrews, J. (2022). Reduction of Petri net maintenance modeling complexity via Approximate Bayesian Computation. Reliability Engineering and System Safety, 222, Article 108365. https://doi.org/10.1016/j.ress.2022.108365

The accurate modeling of engineering systems and processes using Petri nets often results in complex graph representations that are computationally intensive, limiting the potential of this modeling tool in real life applications. This paper presents... Read More about Reduction of Petri net maintenance modeling complexity via Approximate Bayesian Computation.

Railway track availability modelling with opportunistic maintenance practice (2021)
Journal Article
Davies, B., & Andrews, J. (2022). Railway track availability modelling with opportunistic maintenance practice. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 236(8), 907-919. https://doi.org/10.1177/09544097211047663

The geometry of railway track must be maintained within certain standards in order to provide a highly available network, as well as good ride comfort and safety for all rail users. Modelling is well utilised as part of asset management tools in expl... Read More about Railway track availability modelling with opportunistic maintenance practice.