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Fault Tree analysis including component dependencies
Presentation / Conference Contribution
Tolo, S., & Andrews, J. (2022, August). Fault Tree analysis including component dependencies. Presented at 32nd European Safety and Reliability Conference (ESREL 2022), Dublin, Ireland

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.

An Integrated Modelling Framework for Complex Systems Safety Analysis: Case-Studies
Presentation / Conference Contribution
Tolo, S., & Andrews, J. (2022, August). An Integrated Modelling Framework for Complex Systems Safety Analysis: Case-Studies. Presented at 32nd European Safety and Reliability Conference (ESREL 2022), Dublin, Ireland

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
Presentation / Conference Contribution
Andrews, J., & Tolo, S. (2022, August). Dynamic and Dependent Tree Theory (D 2 T 2 ): A Fault Tree Analysis Framework. Presented at 32nd European Safety and Reliability Conference (ESREL 2022), Dublin, Ireland

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.

Evolved Methods for Risk Assessment
Presentation / Conference Contribution
Jackson, A., Tolo, S., & Andrews, J. (2021, September). Evolved Methods for Risk Assessment. Presented at 31st European Safety and Reliability Conference, Angers, France

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.

A Modelling Framework for Dynamic Safety Assessment
Presentation / Conference Contribution
Tolo, S., Yan, R., Dunnett, S., & Andrews, J. (2021, September). A Modelling Framework for Dynamic Safety Assessment. Presented at ESREL 2021 - 31st European Safety and Reliability Conference, Angers, France

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.

A Petri Net Methodology for Modeling the Resilience of Nuclear Power Plants
Presentation / Conference Contribution
Yan, R., Dunnett, S., Tolo, S., & Andrews, J. (2021, September). A Petri Net Methodology for Modeling the Resilience of Nuclear Power Plants. Presented at 31st European Safety and Reliability Conference, Angers, France

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.

Modelling the interactions between defect mechanisms on metal bridges
Presentation / Conference Contribution
Calvert, G., Neves, L., Andrews, J., & Hamer, M. (2021, April). Modelling the interactions between defect mechanisms on metal bridges. Presented at 10th International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), Sapporo, Japan

Bridge asset managers have finite resources at their disposal to minimise the risk of structural failure and ensure bridges are maintained to a suitable safety threshold. Any maintenance strategy must be efficient in its use of resources and deliver... Read More about Modelling the interactions between defect mechanisms on metal bridges.

Resilience in the context of Nuclear safety engineering
Presentation / Conference Contribution
Yan, R., Tolo, S., Dunnett, S., Andrews, J., & Patelli, E. (2020, January). Resilience in the context of Nuclear safety engineering. Presented at RAMS 2020: 66th Annual Reliability and Maintainability Symposium, Palm Springs, California, USA

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.

Vulnerability assessment modelling for railway networks
Presentation / Conference Contribution
Meesit, R., & Andrews, J. (2018, June). Vulnerability assessment modelling for railway networks. Presented at 10th IMA International Conference on Modelling in Industrial Maintenance and Reliability (MIMAR 2018), Manchester, UK

Railway networks are prone to many different potential disruptive events such as technical failures (e.g. the failure of aging components), natural disasters (e.g. flooding) and intentional man-made disasters (e.g. trespass and suicide). Assessing th... Read More about Vulnerability assessment modelling for railway networks.

Petri Nets and Pseudo-Bond Graphs for a Nuclear Reactor Primary Coolant System
Presentation / Conference Contribution
Wootton, M. J., Andrews, J., Lloyd, A. L., Smith, R., Arul, A. J., Vinod, G., Prasad, S. H., & Garg, V. (2019, September). Petri Nets and Pseudo-Bond Graphs for a Nuclear Reactor Primary Coolant System. Presented at 29th European Safety and Reliability Conference (ESREL 2019), Hannover, Germany

In this paper we demonstrate the application of timed Petri Net methodology to the frequency of initiating faults in the coolant circulation system of a fictional nuclear reactor design. A second model is presented where the Petri Net is coupled with... Read More about Petri Nets and Pseudo-Bond Graphs for a Nuclear Reactor Primary Coolant System.

Development of an extended RAMS framework for railway networks
Presentation / Conference Contribution
Litherland, J., Calvert, G., Andrews, J., & Kirwan, A. (2019, September). Development of an extended RAMS framework for railway networks. Presented at 29th European Safety and Reliability Conference (ESREL 2019), Hannover, Germany

Railway asset managers have finite resources which requires them to make strategic decisions on where, when and how the available budget will be spent on the railway, while ensuring safety limits are maintained and a high level of performance is deli... Read More about Development of an extended RAMS framework for railway networks.

Efficient risk based optimization of large system models using a reduced petri net methodology
Presentation / Conference Contribution
Naybour, S., Andrews, J., & Chiachio-Ruano, M. (2019, September). Efficient risk based optimization of large system models using a reduced petri net methodology. Presented at 29th European Safety and Reliability Conference (ESREL 2019), Hannover, Germany

The methodology presented in this paper is a two-stage optimization approach that can be applied to large system level models, in this case using a Stochastic Petri Net (SPN) framework, to produce an equivalent model response at a reduced computation... Read More about Efficient risk based optimization of large system models using a reduced petri net methodology.

A petri net methodology for modelling the maintenance of railway route sections
Presentation / Conference Contribution
Litherland, J., & Andrews, J. (2019, September). A petri net methodology for modelling the maintenance of railway route sections. Presented at 29th European Safety and Reliability Conference (ESREL 2019), Hannover, Germany

Railway utilization is increasing. In 2017-18 there were over 1.7 billion passenger journeys made on the UK railway network, more than double the number made in 1995. Therefore getting maximum performance from the existing network by streamlining mai... Read More about A petri net methodology for modelling the maintenance of railway route sections.

Nuclear Facilities and Cyber Threats
Presentation / Conference Contribution
Tolo, S., & Andrews, J. (2019, September). Nuclear Facilities and Cyber Threats. Presented at 29th European Safety and Reliability Conference (ESREL 2019), Hannover, Germany

The exponential growth of digital technologies experienced in the last decades has shaped contemporary societies so thoroughly to earn the definition of digital revolution or third industrial revolution. Along with the penetration rate of digital tec... Read More about Nuclear Facilities and Cyber Threats.