ARCHITECTURE DESIGN

Dr. Noman Islam

INTRODUCTION

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• Chapter introduces Architectural Design.
• Focus on defining system structure.
• Translate requirements into architecture.
• Importance of architecture.
• Guides implementation and design decisions.
• Ensures maintainability and scalability.
• Goal.
• Learn architectural styles and patterns.
• Understand component interactions.

ARCHITECTURAL DESIGN OVERVIEW

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• Architecture represents high-level structure.
• Defines components and their relationships.
• Provides blueprint for system development.
• Connects requirements and design.
• Ensures functional and non-functional requirements are met.
• Supports system quality attributes.
• Iterative process.
• Refine architecture with feedback.
• Incorporate evolving requirements.

ARCHITECTURE ACTIVITIES

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• Define architectural components.
• Identify modules, subsystems, layers.
• Specify responsibilities.
• Specify interfaces and interactions.
• Define communication patterns.
• Ensure compatibility and data flow.
• Evaluate architectural alternatives.
• Assess trade-offs.
• Select optimal design.

ARCHITECTURAL STYLES 1

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• Layered architecture.
• Organize system into layers.
• Separation of concerns.
• Client-server architecture.
• Servers provide services.
• Clients consume services.
• Pipe-and-filter architecture.
• Data flows through processing elements.
• Supports flexible processing.

ARCHITECTURAL STYLES 2

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• Model-View-Controller (MVC).
• Separates data, UI, and control logic.
• Enhances maintainability.
• Event-driven architecture.
• Components communicate via events.
• Supports asynchronous behavior.
• Service-oriented architecture (SOA).
• Services provide reusable functionality.
• Loose coupling between components.

DESIGN DECISIONS IN ARCHITECTURE

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• Trade-offs between performance and maintainability.
• Optimized components may reduce readability.
• Simpler design may affect performance.
• Scalability considerations.
• Plan for increasing load.
• Support distributed deployment.
• Security and reliability.
• Design for safe operation.
• Handle failures gracefully.

COMPONENT INTERACTIONS

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• Define communication mechanisms.
• Synchronous vs asynchronous.
• Shared data or message passing.
• Interface design.
• Clearly specify input/output.
• Define contracts for modules.
• Dependency management.
• Minimize tight coupling.
• Maximize modularity.

ARCHITECTURAL VIEWS

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• Module view.
• Focus on decomposition.
• Defines module structure.
• Component-and-connector view.
• Focus on runtime interaction.
• Defines communication paths.
• Allocation view.
• Shows mapping to hardware or processes.
• Supports deployment planning.

DOCUMENTATION OF ARCHITECTURE

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• Architecture description document (ADD).
• Captures all design decisions.
• Includes diagrams and rationale.
• Use of UML diagrams.
• Component diagrams for structure.
• Sequence diagrams for interactions.
• Maintain traceability.
• Link architecture to requirements.
• Support verification and validation.

ARCHITECTURE EVALUATION 1

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• Assess quality attributes.
• Performance, reliability, security.
• Check maintainability and flexibility.
• Scenario-based evaluation.
• Use cases for testing architecture.
• Simulate interactions and load.
• Identify risks.
• Detect potential design flaws.
• Mitigate early in development.

ARCHITECTURE EVALUATION 2

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• Prototyping.
• Build small parts to test design.
• Evaluate technical feasibility.
• Simulation and modeling.
• Predict performance.
• Verify architectural decisions.
• Peer reviews.
• Stakeholders and experts assess design.
• Provide improvement suggestions.

PATTERNS IN ARCHITECTURAL DESIGN 1

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• Recurrent solutions to common problems.
• Provide proven templates.
• Reduce design errors.
• Examples: MVC, Observer, Layered.
• Address standard challenges.
• Enhance communication and reuse.
• Benefits.
• Faster design decisions.
• Improves quality and maintainability.

PATTERNS IN ARCHITECTURAL DESIGN 2

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• Client-server pattern.
• Separates clients and services.
• Supports distributed systems.
• Microservices pattern.
• Independent deployable services.
• Promotes scalability and flexibility.
• Event-driven pattern.
• Components react to events.
• Supports decoupling and async operations.

ARCHITECTURAL STYLES SELECTION

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• Consider system requirements.
• Functional and non-functional needs.
• Quality attributes like performance.
• Evaluate trade-offs.
• Flexibility vs complexity.
• Performance vs maintainability.
• Select optimal style.
• Match project context.
• Ensure stakeholder alignment.

SOFTWARE ARCHITECTURE AND AGILE

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• Incremental architectural design.
• Develop architecture in iterations.
• Refine based on feedback.
• Architecture runway.
• Support future features.
• Avoid bottlenecks.
• Lightweight documentation.
• Capture essential details only.
• Focus on working system.

DISTRIBUTED ARCHITECTURE

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• Consider networked systems.
• Clients and servers communicate over network.
• Handle latency and failures.
• Partitioning and replication.
• Divide functionality across nodes.
• Ensure redundancy for reliability.
• Consistency and synchronization.
• Data coherence across nodes.
• Minimize conflicts and delays.

QUALITY ATTRIBUTES IN ARCHITECTURE

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• Performance, scalability, reliability.
• Evaluate against expected load.
• Plan for growth.
• Security and availability.
• Prevent unauthorized access.
• Ensure continuous operation.
• Maintainability and modifiability.
• Simplify changes.
• Support future evolution.

ARCHITECTURE DOCUMENTATION TOOLS

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• CASE tools and UML support.
• Visualize components and interactions.
• Maintain design consistency.
• Architecture repositories.
• Store reusable components.
• Support versioning.
• Collaboration platforms.
• Team access and updates.
• Enable stakeholder feedback.

CHALLENGES IN ARCHITECTURAL DESIGN

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• Balancing trade-offs.
• Performance vs maintainability.
• Flexibility vs complexity.
• Evolving requirements.
• Architecture must adapt.
• Support iterative changes.
• Communication gaps.
• Stakeholders misinterpret diagrams.
• Ensure clarity through documentation.

CHAPTER SUMMARY

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• Architecture defines high-level system structure.
• Components, connectors, and views.
• Bridges requirements and implementation.
• Selection of styles and patterns is critical.
• Use proven templates.
• Consider quality attributes.
• Evaluation, documentation, and management ensure success.
• Traceability and validation.
• Supports scalable, maintainable systems.