| 1. |
- Flammini, Francesco, Senior Lecturer, 1978-, et al.
(författare)
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A Petri Net pattern-oriented approach for the design of physical protection systems
- 2014
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Ingår i: Computer Safety, Reliability, and Security. SAFECOMP 2014. - Cham : Springer. - 9783319105055 ; , s. 230-245
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Konferensbidrag (refereegranskat)abstract
- The design of complex Physical Protection Systems (PPSs) still raises some challenges despite the high number of technologies for smart surveillance. One reason is the lack of effective methodologies able to support the PPS designer in evaluating the effectiveness of the system on varying design choices. Indeed, an estimation of the system vulnerability should be performed in the early phases of the PPS design. This paper introduces a model-based methodology for the quantitative estimation of the vulnerability of a PPS. The proposed methodology clearly defines a compositional approach which takes advantage from the usage of predefined patterns for the creation of vulnerability models. In particular, the paper proposes some Petri Net patterns able to capture the behavioural aspects of several assets and actors involved in attacking/defending scenarios. © 2014 Springer International Publishing.
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| 2. |
- Graydon, Patrick
(författare)
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Towards a clearer understanding of context and its role in assurance argument confidence
- 2014
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Ingår i: Lecture Notes in Computer Science, vol. 8666. - Cham : Springer International Publishing. - 9783319105055 ; , s. 139-154
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Konferensbidrag (refereegranskat)abstract
- The Goal Structuring Notation (GSN) is a popular graphical notation for recording safety arguments. One of GSN's key innovations is a context element that links short phrases used in the argument to detail available elsewhere. However, definitions of the context element admit multiple interpretations and conflict with guidance for building assured safety arguments. If readers do not share an understanding of the meaning of context that makes context's impact on the main safety claim clear, confidence in safety might be misplaced. In this paper, we analyse the definitions and usage of GSN context elements, identify contradictions and vagueness, propose a more precise definition, and make updated recommendations for assured safety argument structure.
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| 3. |
- Sljivo, Irfan, et al.
(författare)
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Generation of Safety Case Argument-Fragments from Safety Contracts
- 2014
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Ingår i: Computer Safety, Reliability, and Security. - Cham : Springer International Publishing. - 9783319105055 ; , s. 170-185
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Konferensbidrag (refereegranskat)abstract
- Certification of safety-critical systems is a costly and time-consuming activity. To reduce the cost of certification and time-to-market, composable safety certification envisions reuse of safety case argument-fragments together with safety-relevant components developed out-of-context. The argument-fragments could cover safety aspects relevant for different contexts in which the component can be used. Creating argument-fragments for such out-of-context components is also time-consuming and currently no satisfying approach exists to facilitate their automatic generation. In this work we propose (semi-)automatic generation of argument-fragments from assumption/guarantee safety contracts. We use the contracts to capture the safety claims related to the component, including supporting evidence. We provide an overview of the argument-fragment architecture and rules for automatic generation, including their application in an illustrative example. By automating generation of argument-fragments, we enable safety engineers to focus on increasing the confidence in the knowledge about the system, rather than documenting a safety case.
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