Architecturebased Development

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Architecture-based Development
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Steps of the Process
Elicit Architectural Requirements
Document the Architecture
Design the Architecture
Analyze the Architecture
Realize the Architecture
Maintain the Architecture
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Elicitating Architectural Requirements

• Identify Architectural Drivers
• Architectural Requirements are consequences of
  these
• Architectural Requirements derive from one of
  three sources
• Quality goals for the system
• i.e., non-functional requirements
• Business goals of the system
• Business goals of users of the system

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Scenarios

• Behavioural Requirements
• Use cases for systems
• Abstract use cases for product lines
• Quality-Specific Scenarios
• Change scenarios modifiability
• Threat scenarios security
• Response-time scenarios performance
• Error-handling scenarios reliability
• Degradation scenarios availability

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Scenario-Elicitation Matrix
Quality attributes
Stakeholders
st2
st1
Q1
Q2
Q3
sc1
Scenarios
sc2
sc3
sc1
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Designing the Architecture

• Five structures identified
• Functional structure
• Code structure
• Concurrency structure
• Physical structure
• Development structure

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Relationship Between Structures and Qualities
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Design Process

• Develop list of candidate subsystems
• For each architectural requirement enumerate
  architectural choices
• Select and minimise architectural choices
• Choose actual subsystems
• Populate concurrency structure
• Validate
• using Quality Scenarios

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Documenting the Architecture

• Documentation characteristics
• Documentation should be complete and navigable
• Infrastructure documented integrally
• A number of use cases must be mapped onto
  architecture
• Architecture and its use in target systems must
  be bound by specified constraints
• All architectural documentation must be made
  available to ALL stakeholders

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Analyzing the Architecture

• Utilises the Architectural Tradeoff Analysis
  Method (ATAM)
• ATAM techniques
• Scenario elicitation
• Architecture elicitation
• Analysis

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Realizing and Maintaining the Architecture

• Realization requires structuring organisation
  teams around the chosen subsystems
• see., Conways Law
• Maintenance often involves reverse engineering
• Many architectural elements have no direct
  representation in code