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CSE 503: Software Engineering
Software Architecture
Jonathan Aldrich
University of Washington
Department of Computer Science and Engineering
Winter 2002
Programming in the Large vs.
Programming in the Small
• Large systems bring different challenges
• What problems have you experienced?
– Where/how do I extend the system?
– What invariants hold of a large data structure?
– What are a module’s clients/what does it use?
– Tight coupling
– Large interfaces
Programming in the Large vs.
Programming in the Small
• Large systems bring different challenges
• How do you deal with them?
– Imitate examples
– Have someone explain/draw a picture
– Trace through code
– Grep or other tools
– Read documentation
Software Architecture
• The highest level of design
– The gross organization of a software system
– Issues: decomposition, control flow,
communication, concurrency, distribution
• A set of components, connections between
the components, and constraints on how
they interact
parser codegen scanner
Compiler
Benefits of Architecture
• Specification of high-level system design
– Program understanding
– Analysis
– Language and tool support
• Taxonomy of system design
– Advantages/disadvantages
– Capturing design experience
– Relationship between systems
parser codegen scanner
Compiler Architectural Styles
• System-level design patterns
– Client-server or 3-tier
– Layered system
– Pipeline architecture
• Represent design knowledge
– Vocabulary of concepts
– Constraints on implementation
– Benefits/drawbacks of alternatives
