eusec tool vendors challenge adie ditchburn jon chard 19 sep 2006
TRANSCRIPT
EuSEC Tool Vendors’ Challenge
Adie Ditchburn
Jon Chard
19 Sep 2006
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Approach
• Discuss Method of Deriving Requirements
– Structure
– Role of Modelling
• Relationship of Models to requirements
• Demonstrate DOORS Structure
– Database Level
– Module Level
• Demonstrate Modelling using TAU
– Use Case to System Level Activity Models
– Logical System Structure Models
• Discuss Information Traceability
• Demonstrate Traceability in DOORS
– Traceability Reports
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SystemRequirements
AgreeRequirements
QualificationStrategy
Analyze&
Model
StakeholderRequirements
AcceptanceStrategy
AgreeRequirements
SystemModels
AnalysisResults
DeriveRequirements& Qualification
Strategy
Deriving System Requirements
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Understanding your requirements
• Don’t just ‘list’ requirements, use structure to understand them
• Organise similar requirements into sections within documents
• Use structure to discover:
– Context (overall situation in which the requirement occurs)
• Allows you to see the “whole picture”
– Duplications (same requirement stated twice)
• Causes work to be performed twice
• Can lead to conflicting requirements
• Doubles your maintenance cost
– Omissions (missing requirements)
• Unstated requirements become missing functionality
• Could cause shortcomings in non-functional areas such as performance, reliability, ease of use - that can not be “re-engineered” back into the system once developed
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Functionalmodeling
Functionalmodeling
Functionalmodeling
Models Bridge Layers of Requirements
Requirements layer
Modeling layer
Requirements layer
Modeling layer
Requirements layer
Modeling layer
Requirements layer
e.g Goal / Usage modeling
e.g. Functionalmodeling
SponsorRequirements
DesignSpecification
SystemRequirements
Statementof need
e.g. Performancemodeling
Concept: Requirements and Modeling
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‘Tool Vendor Challenge’ CCC Layers of Requirements and Models
ChallengeStatement
Concept: Requirements and Modeling
Stakeholder Requirements
System Requirements
Sub-System Requirements
Constructed in DOORS
Functionalmodeling
Functionalmodeling
Functionalmodeling
Use Case modeling
Activitymodeling
Functionalmodeling
Constructed in TAU
Implementation
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DOORS and TAU Demonstrations
Demonstration of Requirements Structure in DOORS
Demonstration of SysML Modelling in TAU
Over to you Jon
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Requirements visualization and satisfaction through modelling in Tau with traceability to DOORS
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System black-box use cases in Tau SysML
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Example system block structure in Tau SysML
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Example configuration block internal structure diagram
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State machine description of subsystem block behaviour
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Information Traceability
• INFORMATION TRACEABILITY:
• Understanding how high-level objectives are transformed into low-level goals.
e.g. in business terms: Understanding how
• business vision interpreted
as• business objectives
implemented as
• business processes
e.g. in systems engineering:Understanding how• user requirements
satisfied by• system requirements
implemented as• design artifacts
implemented as• components
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Benefits of Information Traceability
• Greater confidencethat objectives are being met.
• Ability to manage changethrough ability to access change impact.
• Greater accountabilityof subordinate organisations/suppliers.
• Ability to track progress / statusparticularly in the formative stages of project.
• Ability to deliver valuethrough cost/benefit analysis.
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DOORS Demonstration
Demonstration of Production of Traceability Reports
Once again Jon
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Use of DOORS traceability analysis tools to show requirements satisfaction through SysML model.