Systematic hierarchical analysis of requirements for critical systems
Systematic hierarchical analysis of requirements for critical systems
Safety and security are key considerations in the design of critical systems. Requirements analysis methods rely on the expertise and experience of human intervention to make critical judgements. While human judgement is essential to an analysis method, it is also important to ensure a degree of formality so that we reason about safety and security at early stages of analysis and design, rather than detect problems later. In this paper, we present a hierarchical and incremental analysis process that aims to justify the design and flow-down of derived critical requirements arising from safety hazards and security vulnerabilities identified at the system level. The safety and security analysis at each level uses STPA-style action analysis to identify hazards and vulnerabilities. At each level, we verify that the design achieves the safety or security requirements by backing the analysis with formal modelling and proof using Event-B refinement. The formal model helps to identify hazards/vulnerabilities arising from the design and how they relate to the safety accidents/security losses being considered at this level. We then re-apply the same process to each component of the design in a hierarchical manner. Thus, we use hazard and vulnerability analysis, together with refinement-based formal modelling and verification, to drive the design, replacing the system level requirements with component requirements. In doing so, we decompose critical system-level requirements down to component-level requirements, transforming them from abstract system level requirements, towards concrete solutions that we can implement correctly so that the hazards/vulnerabilities are mitigated.
Event-B, Hazards, Requirements, Safety, Security, STPA, Vulnerabilities
Salehi Fathabadi, Asieh
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Snook, Colin
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Dghaym, Dana
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Hoang, Son
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Alotaibi, Fahad
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Butler, Michael
54b9c2c7-2574-438e-9a36-6842a3d53ed0
12 March 2024
Salehi Fathabadi, Asieh
b799ee35-4032-4e7c-b4b2-34109af8aa75
Snook, Colin
b2055316-9f7a-4b31-8aa1-be0710046af2
Dghaym, Dana
f37068fe-d8f7-4925-a72f-70d91d750638
Hoang, Son
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Alotaibi, Fahad
3606f09d-b071-47de-b0c2-f9784f7b1abd
Butler, Michael
54b9c2c7-2574-438e-9a36-6842a3d53ed0
Salehi Fathabadi, Asieh, Snook, Colin, Dghaym, Dana, Hoang, Son, Alotaibi, Fahad and Butler, Michael
(2024)
Systematic hierarchical analysis of requirements for critical systems.
Innovations in Systems and Software Engineering.
(doi:10.1007/s11334-024-00551-8).
Abstract
Safety and security are key considerations in the design of critical systems. Requirements analysis methods rely on the expertise and experience of human intervention to make critical judgements. While human judgement is essential to an analysis method, it is also important to ensure a degree of formality so that we reason about safety and security at early stages of analysis and design, rather than detect problems later. In this paper, we present a hierarchical and incremental analysis process that aims to justify the design and flow-down of derived critical requirements arising from safety hazards and security vulnerabilities identified at the system level. The safety and security analysis at each level uses STPA-style action analysis to identify hazards and vulnerabilities. At each level, we verify that the design achieves the safety or security requirements by backing the analysis with formal modelling and proof using Event-B refinement. The formal model helps to identify hazards/vulnerabilities arising from the design and how they relate to the safety accidents/security losses being considered at this level. We then re-apply the same process to each component of the design in a hierarchical manner. Thus, we use hazard and vulnerability analysis, together with refinement-based formal modelling and verification, to drive the design, replacing the system level requirements with component requirements. In doing so, we decompose critical system-level requirements down to component-level requirements, transforming them from abstract system level requirements, towards concrete solutions that we can implement correctly so that the hazards/vulnerabilities are mitigated.
Text
s11334-024-00551-8
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Accepted/In Press date: 2 February 2024
Published date: 12 March 2024
Additional Information:
Publisher Copyright:
© The Author(s) 2024.
Keywords:
Event-B, Hazards, Requirements, Safety, Security, STPA, Vulnerabilities
Identifiers
Local EPrints ID: 488101
URI: http://eprints.soton.ac.uk/id/eprint/488101
ISSN: 1614-5046
PURE UUID: fe0a888e-519a-4370-b9dd-39c77c973ee9
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Date deposited: 15 Mar 2024 17:45
Last modified: 02 May 2024 01:56
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Contributors
Author:
Asieh Salehi Fathabadi
Author:
Colin Snook
Author:
Dana Dghaym
Author:
Son Hoang
Author:
Fahad Alotaibi
Author:
Michael Butler
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