52 research outputs found
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Using Structured Assurance Case Approach to Analyse Security and Reliability of Critical Infrastructures
The evaluation of the security, reliability and resilience of critical infrastruc-tures (CI) faces a wide range of challenges ranging from the scale and tempo of attacks to the need to address complex and interdependent systems of sys-tems. Model-based approaches and probabilistic design are fundamental to the evaluation of CI and we need to know whether we can trust these mod-els. This paper presents an approach we are developing to justify the models used to assure CI using structured assurance cases based on Claims, Argu-ments and Evidence (CAE). The modelling and quantitative evaluation of the properties are supported by the Preliminary Interdependency Analysis (PIA) method and platform applied to a case study – a reference power transmission network enhanced with an industrial distributed system of monitoring, protection and control. We discuss the usefulness of the model-ling and assurance case structuring approaches, some findings from the case study, and outline the directions of further work
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Tool Support for Assurance Case Building Blocks, Providing a Helping Hand with CAE
This paper presents a tool for structuring arguments in assurance cases. The tool is designed to support the methodology of Claims-Arguments-Evidence (CAE) Building Blocks that provides a series of archetypal CAE fragments to help structure cases more formally and systematically. It assists with the de-velopment and maintenance of structured assurance cases by providing facil-ities to manage CAE blocks and partially automate the generation of claim structures. In addition to the tool, new visual guidelines called “Helping hand” is provided to assist in applying the building blocks. The tool has been implemented on the Adelard ASCE platform. The target users are assurance case developers and reviewers. The tool and associated methodology can also be useful for people learning how to structure cases in a more rigorous and systematic manner
An Assurance Framework for Independent Co-assurance of Safety and Security
Integrated safety and security assurance for complex systems is difficult for
many technical and socio-technical reasons such as mismatched processes,
inadequate information, differing use of language and philosophies, etc.. Many
co-assurance techniques rely on disregarding some of these challenges in order
to present a unified methodology. Even with this simplification, no methodology
has been widely adopted primarily because this approach is unrealistic when met
with the complexity of real-world system development.
This paper presents an alternate approach by providing a Safety-Security
Assurance Framework (SSAF) based on a core set of assurance principles. This is
done so that safety and security can be co-assured independently, as opposed to
unified co-assurance which has been shown to have significant drawbacks. This
also allows for separate processes and expertise from practitioners in each
domain. With this structure, the focus is shifted from simplified unification
to integration through exchanging the correct information at the right time
using synchronisation activities
A PRISMA-driven systematic mapping study on system assurance weakeners
Context: An assurance case is a structured hierarchy of claims aiming at
demonstrating that a given mission-critical system supports specific
requirements (e.g., safety, security, privacy). The presence of assurance
weakeners (i.e., assurance deficits, logical fallacies) in assurance cases
reflects insufficient evidence, knowledge, or gaps in reasoning. These
weakeners can undermine confidence in assurance arguments, potentially
hindering the verification of mission-critical system capabilities.
Objectives: As a stepping stone for future research on assurance weakeners,
we aim to initiate the first comprehensive systematic mapping study on this
subject. Methods: We followed the well-established PRISMA 2020 and SEGRESS
guidelines to conduct our systematic mapping study. We searched for primary
studies in five digital libraries and focused on the 2012-2023 publication year
range. Our selection criteria focused on studies addressing assurance weakeners
at the modeling level, resulting in the inclusion of 39 primary studies in our
systematic review.
Results: Our systematic mapping study reports a taxonomy (map) that provides
a uniform categorization of assurance weakeners and approaches proposed to
manage them at the modeling level.
Conclusion: Our study findings suggest that the SACM (Structured Assurance
Case Metamodel) -- a standard specified by the OMG (Object Management Group) --
may be the best specification to capture structured arguments and reason about
their potential assurance weakeners
Is current incremental safety assurance sound ?
International audienceIncremental design is an essential part of engineering. Without it, engineering would not likely be an economic, nor an effective, aid to economic progress. Further, engineering relies on this view of incrementality to retain the reliability attributes of the engineering method. When considering the assurance of safety for such artifacts, it is not surprising that the same economic and reliability arguments are deployed to justify an incremental approach to safety assurance. In a sense, it is possible to argue that, with engineering artifacts becoming more and more complex, it would be economically disastrous to not “do” safety incrementally. Indeed, many enterprises use such an incremental approach, reusing safety artifacts when assuring incremental design changes. In this work, we make some observations about the inadequacy of this trend and suggest that safety practices must be rethought if incremental safety approaches are ever going to be fit for purpose. We present some examples to justify our position and comment on what a more adequate approach to incremental safety assurance may look like
How to increase efficiency with the certification of process compliance
Certification as well as self-assessment of safety-critical systems is an expensive and time-consuming activity due to the necessity of providing numerous deliverables. These deliverables can be process-related or product-related. Process-related deliverables are aimed at showing compliance with normative documents (e.g., safety standards), which impose specific requirements on the development process (e.g., reference models for the safety life-cycles).
In this lecture, we limit our attention to process-related deliverables and we propose a solution aimed at reducing time and cost related to their provision. Our solution consists of the combination of three approaches: the safety-oriented process line engineering approach, the process-based argumentation line approach, and the model driven certification-oriented approach. More specifically, we define how these three approaches are combined and which techniques, tools and guidelines should be used to implement the resulting approach. Then, via small-sized but realistic process-fragments, we illustrate it. Finally, we present a roadmap for future research directions.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
The Last Decade in Review: Tracing the Evolution of Safety Assurance Cases through a Comprehensive Bibliometric Analysis
Safety assurance is of paramount importance across various domains, including
automotive, aerospace, and nuclear energy, where the reliability and
acceptability of mission-critical systems are imperative. This assurance is
effectively realized through the utilization of Safety Assurance Cases. The use
of safety assurance cases allows for verifying the correctness of the created
systems capabilities, preventing system failure. The latter may result in loss
of life, severe injuries, large-scale environmental damage, property
destruction, and major economic loss. Still, the emergence of complex
technologies such as cyber-physical systems (CPSs), characterized by their
heterogeneity, autonomy, machine learning capabilities, and the uncertainty of
their operational environments poses significant challenges for safety
assurance activities. Several papers have tried to propose solutions to tackle
these challenges, but to the best of our knowledge, no secondary study
investigates the trends, patterns, and relationships characterizing the safety
case scientific literature. This makes it difficult to have a holistic view of
the safety case landscape and to identify the most promising future research
directions. In this paper, we, therefore, rely on state-of-the-art bibliometric
tools(e.g., VosViewer) to conduct a bibliometric analysis that allows us to
generate valuable insights, identify key authors and venues, and gain a birds
eye view of the current state of research in the safety assurance area. By
revealing knowledge gaps and highlighting potential avenues for future
research, our analysis provides an essential foundation for researchers,
corporate safety analysts, and regulators seeking to embrace or enhance safety
practices that align with their specific needs and objectives
Combined automotive safety and security pattern engineering approach
Automotive systems will exhibit increased levels of automation as well as ever tighter integration with other vehicles, traffic infrastructure, and cloud services. From safety perspective, this can be perceived as boon or bane - it greatly increases complexity and uncertainty, but at the same time opens up new opportunities for realizing innovative safety functions. Moreover, cybersecurity becomes important as additional concern because attacks are now much more likely and severe. However, there is a lack of experience with security concerns in context of safety engineering in general and in automotive safety departments in particular. To address this problem, we propose a systematic pattern-based approach that interlinks safety and security patterns and provides guidance with respect to selection and combination of both types of patterns in context of system engineering. A combined safety and security pattern engineering workflow is proposed to provide systematic guidance to support non-expert engineers based on best practices. The application of the approach is shown and demonstrated by an automotive case study and different use case scenarios.EC/H2020/692474/EU/Architecture-driven, Multi-concern and Seamless Assurance and Certification of Cyber-Physical Systems/AMASSEC/H2020/737422/EU/Secure COnnected Trustable Things/SCOTTEC/H2020/732242/EU/Dependability Engineering Innovation for CPS - DEIS/DEISBMBF, 01IS16043, Collaborative Embedded Systems (CrESt
Studying Software Engineering Patterns for Designing Machine Learning Systems
Machine-learning (ML) techniques have become popular in the recent years. ML
techniques rely on mathematics and on software engineering. Researchers and
practitioners studying best practices for designing ML application systems and
software to address the software complexity and quality of ML techniques. Such
design practices are often formalized as architecture patterns and design
patterns by encapsulating reusable solutions to commonly occurring problems
within given contexts. However, to the best of our knowledge, there has been no
work collecting, classifying, and discussing these software-engineering (SE)
design patterns for ML techniques systematically. Thus, we set out to collect
good/bad SE design patterns for ML techniques to provide developers with a
comprehensive and ordered classification of such patterns. We report here
preliminary results of a systematic-literature review (SLR) of good/bad design
patterns for ML
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