All Outputs (36)

Safety-Security Co-Engineering Framework (2023)
Report
Aslansefat, K., Gerasimou, S., Hamibi, H., Matragkas, N., Michalodimitrakis, E., Papadopoulos, Y., Papoutsakis, M., & Walker, M. (2023). Safety-Security Co-Engineering Framework. European Commission

Executive Summary:
The advantages of a model-based approach for safety have been clear for many years now. However, security analysis is typically less formal and more ad-hoc; it may involve systematic processes but these are not generally tied into... Read More about Safety-Security Co-Engineering Framework.

Safety Analysis Concept and Methodology for EDDI development (Initial Version) (2023)
Report
Aslansefat, K., Gerasimou, S., Michalodimi-trakis, E., Papoutsakis, M., Reich, J., Sorokos, I., Walker, M., & Papadopoulos, Y. (2023). Safety Analysis Concept and Methodology for EDDI development (Initial Version). European Comission

Executive Summary:
This deliverable describes the proposed safety analysis concept and accompanying methodology to be defined in the SESAME project. Three overarching challenges to the development of safe and secure multi-robot systems are identifie... Read More about Safety Analysis Concept and Methodology for EDDI development (Initial Version).

Explaining black boxes with a SMILE: Statistical Model-agnostic Interpretability with Local Explanations (2023)
Journal Article
Aslansefat, K., Hashemian, M., Walker, M., Akram, M. N., Sorokos, I., & Papadopoulos, Y. (2023). Explaining black boxes with a SMILE: Statistical Model-agnostic Interpretability with Local Explanations. IEEE Software, https://doi.org/10.1109/MS.2023.3321282

Machine learning is currently undergoing an explosion in capability, popularity, and sophistication. However, one of the major barriers to widespread acceptance of machine learning (ML) is trustworthiness: most ML models operate as black boxes, their... Read More about Explaining black boxes with a SMILE: Statistical Model-agnostic Interpretability with Local Explanations.

Dependability Analysis Using Temporal Fault Trees and Monte Carlo Simulation (2021)
Book Chapter
Edifor, E., Gordon, N., & Walker, M. (2021). Dependability Analysis Using Temporal Fault Trees and Monte Carlo Simulation. In W. Zamojski, J. Mazurkiewicz, J. Sugier, T. Walkowiak, & J. Kacprzyk (Eds.), Theory and Engineering of Dependable Computer Systems and Networks (86-96). Cham: Springer. https://doi.org/10.1007/978-3-030-76773-0_9

The safety and reliability of high-consequence systems is an issue of utmost importance to engineers because such systems can have catastrophic effects if they fail. Fault Tree Analysis (FTA) is a well-known probabilistic technique for assessing the... Read More about Dependability Analysis Using Temporal Fault Trees and Monte Carlo Simulation.

Dynamic system safety analysis in HiP-HOPS with Petri Nets and Bayesian Networks (2018)
Journal Article
Papadopoulos, Y., Walker, M., & Kabir, S. (2018). Dynamic system safety analysis in HiP-HOPS with Petri Nets and Bayesian Networks. Safety science, 105, 55-70. https://doi.org/10.1016/j.ssci.2018.02.001

© 2018 Elsevier Ltd Dynamic systems exhibit time-dependent behaviours and complex functional dependencies amongst their components. Therefore, to capture the full system failure behaviour, it is not enough to simply determine the consequences of diff... Read More about Dynamic system safety analysis in HiP-HOPS with Petri Nets and Bayesian Networks.

A model-based extension to HiP-HOPS for dynamic fault propagation studies (2017)
Journal Article
Kabir, S., Papadopoulos, Y., Walker, M., Parker, D., Aizpurua, J. I., Lampe, J., & Rüde, E. (2017). A model-based extension to HiP-HOPS for dynamic fault propagation studies. Lecture notes in computer science, 10437 LNCS, 163-178. https://doi.org/10.1007/978-3-319-64119-5_11

HiP-HOPS is a model-based approach for assessing the dependability of safety-critical systems. The method combines models, logic, probabilities and nature-inspired algorithms to provide advanced capabilities for design optimisation, requirement alloc... Read More about A model-based extension to HiP-HOPS for dynamic fault propagation studies.

Fuzzy temporal fault tree analysis of dynamic systems (2016)
Journal Article
Kabir, S., Papadopoulos, Y., Walker, M., Rüde, E., & Securius, P. (2016). Fuzzy temporal fault tree analysis of dynamic systems. International Journal of Approximate Reasoning, 77, 20-37. https://doi.org/10.1016/j.ijar.2016.05.006

Fault tree analysis (FTA) is a powerful technique that is widely used for evaluating system safety and reliability. It can be used to assess the effects of combinations of failures on system behaviour but is unable to capture sequence dependent dynam... Read More about Fuzzy temporal fault tree analysis of dynamic systems.

A synthesis of logic and bio-inspired techniques in the design of dependable systems (2016)
Journal Article
Papadopoulos, Y., Walker, M., Parker, D., Sharvia, S., Bottaci, L., Kabir, S., Azevedo, L., & Sorokos, I. (2016). A synthesis of logic and bio-inspired techniques in the design of dependable systems. Annual Reviews in Control, 41, 170-182. https://doi.org/10.1016/j.arcontrol.2016.04.008

Much of the development of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, can be attributed to the application of advances in formal logic and its application to fault forecast... Read More about A synthesis of logic and bio-inspired techniques in the design of dependable systems.

Quantitative evaluation of Pandora Temporal Fault Trees via Petri Nets (2015)
Journal Article
Kabir, S., Papadopoulos, Y., & Walker, M. (2015). Quantitative evaluation of Pandora Temporal Fault Trees via Petri Nets. IFAC Proceedings Volumes/ International Federation of Automatic Control, 48(21), 458-463. https://doi.org/10.1016/j.ifacol.2015.09.569

© 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. Using classical combinatorial fault trees, analysts are able to assess the effects of combinations of failures on system behaviour but are unab... Read More about Quantitative evaluation of Pandora Temporal Fault Trees via Petri Nets.

Automating allocation of development assurance levels: An extension to HiP-HOPS (2015)
Journal Article
Sorokos, I., Papadopoulos, Y., Azevedo, L., Parker, D., & Walker, M. (2015). Automating allocation of development assurance levels: An extension to HiP-HOPS. IFAC Proceedings Volumes/ International Federation of Automatic Control, 48(7), 9-14. https://doi.org/10.1016/j.ifacol.2015.06.466

Controlling the allocation of safety requirements across a system's architecture from the early stages of development is an aspiration embodied in numerous major safety standards. Manual approaches of applying this process in practice are ineffective... Read More about Automating allocation of development assurance levels: An extension to HiP-HOPS.

Model-based dependability analysis : state-of-the-art, challenges and future outlook (2015)
Book Chapter
Sharvia, S., Kabir, S., Walker, M., & Papadopoulos, Y. (2015). Model-based dependability analysis : state-of-the-art, challenges and future outlook. In I. Mistrik, N. Ali, B. Tekinerdogan, R. Soley, & J. Grundy (Eds.), Software Quality Assurance: In Large Scale and Complex Software-intensive Systems (251-278). Elsevier. https://doi.org/10.1016/B978-0-12-802301-3.00012-0

Abstract: Over the past two decades, the study of model-based dependability analysis has gathered significant research interest. Different approaches have been developed to automate and address various limitations of classical dependability technique... Read More about Model-based dependability analysis : state-of-the-art, challenges and future outlook.

A safety analysis approach to clinical workflows : application and evaluation (2014)
Journal Article
Gordon, N., Kabir, S., Sharvia, S., Walker, M., & Al-Qora’n, L. (in press). A safety analysis approach to clinical workflows : application and evaluation. International Journal of Advanced Computer Science and Applications, 4(3), 82-91. https://doi.org/10.14569/SpecialIssue.2014.040310

Clinical workflows are safety critical workflows as they have the potential to cause harm or death to patients. Their safety needs to be considered as early as possible in the development process. Effective safety analysis methods are required to ens... Read More about A safety analysis approach to clinical workflows : application and evaluation.

Reliability analysis of dynamic systems by translating temporal fault trees into Bayesian networks (2014)
Book Chapter
Kabir, S., Walker, M., & Papadopoulos, Y. (2014). Reliability analysis of dynamic systems by translating temporal fault trees into Bayesian networks. In Model-Based Safety and Assessment; Lecture Notes in Computer Science (96-109). Springer Verlag. https://doi.org/10.1007/978-3-319-12214-4_8

Classical combinatorial fault trees can be used to assess combinations of failures but are unable to capture sequences of faults, which are important in complex dynamic systems. A number of proposed techniques extend fault tree analysis for dynamic s... Read More about Reliability analysis of dynamic systems by translating temporal fault trees into Bayesian networks.

An approach to safety analysis of clinical workflows (2014)
Journal Article
Al-Qora'n, L., Gordon, N., Sharvia, S., Walker, M., & Papadopoulos, Y. (2014). An approach to safety analysis of clinical workflows. Athens Journal of Health, 1(3), 201-216. https://doi.org/10.30958/ajh.1-3-4

A clinical workflow considers the information and processes that are involved in providing a clinical service. They are safety critical since even minor faults have the potential to propagate and consequently cause harm to a patient, or even for a pa... Read More about An approach to safety analysis of clinical workflows.

Safety analysis of clinical workflows: The case of the workflow within a radiology department (2014)
Presentation / Conference Contribution
Gordon, N., Sharvia, S., Walker, M., & Al-Qora'n, L. Safety analysis of clinical workflows: The case of the workflow within a radiology department. Presented at 2014 Science and Information Conference

This paper was originally presented at the Science and Information Conference, 2014, 27-29 August, London. Abstract: Radiology Information Systems (RIS) and Picture Archiving and Communication systems (PACS) are used widely to help in the workflow ma... Read More about Safety analysis of clinical workflows: The case of the workflow within a radiology department.

Enhancing the EAST-ADL error model with HiP-HOPS semantics (2014)
Journal Article
Sharvia, S., Papadopoulos, Y., Chen, D.-J., Walker, M., Yuan, W., & Lönn, H. (2014). Enhancing the EAST-ADL error model with HiP-HOPS semantics. Athens journal of technology & engineering, 1(2), 119-136

EAST-ADL is a domain-specific modelling language for the engineering of automotive embedded systems. The language has abstractions that enable engineers to capture a variety of information about design in the course of the lifecycle — from requiremen... Read More about Enhancing the EAST-ADL error model with HiP-HOPS semantics.

Using simulation to evaluate dynamic systems with weibull or lognormal distributions (2014)
Presentation / Conference Contribution
Edifor, E., Gordon, N., Walker, M., & Papadopoulos, Y. Using simulation to evaluate dynamic systems with weibull or lognormal distributions. Presented at Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX, Brunów, Poland

© Springer International Publishing Switzerland 2014. Most techniques for quantitatively analysing the temporal fault trees of safety-critical systems are used with the assumption that the systems under study have exponentially distributed component... Read More about Using simulation to evaluate dynamic systems with weibull or lognormal distributions.

Exploring the impact of different cost heuristics in the allocation of safety integrity levels (2014)
Journal Article
Azevedo, L. S., Parker, D., Papadopoulos, Y., Walker, M., Sorokos, I., & Araújo, R. E. (2014). Exploring the impact of different cost heuristics in the allocation of safety integrity levels. Lecture notes in computer science, 8822, 70-81. https://doi.org/10.1007/978-3-319-12214-4_6

Contemporary safety standards prescribe processes in which system safety requirements, captured early and expressed in the form of Safety Integrity Levels (SILs), are iteratively allocated to architectural elements. Different SILs reflect different r... Read More about Exploring the impact of different cost heuristics in the allocation of safety integrity levels.

Quantification of temporal fault trees based on fuzzy set theory (2014)
Journal Article
Kabir, S., Edifor, E., Walker, M., & Gordon, N. (2014). Quantification of temporal fault trees based on fuzzy set theory. Advances in Intelligent Systems and Computing, 286, 255-264. https://doi.org/10.1007/978-3-319-07013-1_24

© Springer International Publishing Switzerland 2014. Fault tree analysis (FTA) has been modified in different ways to make it capable of performing quantitative and qualitative safety analysis with temporal gates, thereby overcoming its limitation i... Read More about Quantification of temporal fault trees based on fuzzy set theory.

Quantification of Simultaneous-AND Gates in Temporal Fault Trees (2013)
Presentation / Conference Contribution
Edifor, E., Walker, M., & Gordon, N. Quantification of Simultaneous-AND Gates in Temporal Fault Trees

Fault Tree Analysis has been a cornerstone of safety-critical systems for many years. It has seen various extensions to enable it to analyse dynamic behaviours exhibited by modern systems with redundant components. However, none of these extended FTA... Read More about Quantification of Simultaneous-AND Gates in Temporal Fault Trees.