Term
| what are 6 typical design trade-offs? |
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Definition
1. functionality vs usability
2. cost vs robustness
3. efficiency vs portability
4. rapid development vs functionality
5. cost vs re-usability
6. backward compatibility vs readability |
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Term
| what's the point of system design? |
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Definition
| to transform analysis model to system design model |
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Term
| what are 3 steps for system design? |
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Definition
1. identify design goals
2. model the new system design as a set of subsystems using decomposition
3. address major design goals |
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Term
| what's coupling and coherence? |
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Definition
1. coupling measures dependency among subsystems
2. coherence measures dependency among classes |
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Term
| typically to do we want high or low coupling and coherence? |
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Definition
| we want low coupling but we want high coherence |
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Term
| what's the difference between architectural style and software architecture? |
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Definition
| architectural style is a pattern for a subsystem decomposition and software architecture is a instance of architectural style |
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Term
list 7 architectural styles.
describe each.
what are advantages and disadvantages? |
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Definition
| layered, client/server, 3-tier, p2p, repository, model view controller, pipe and filters |
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Term
what are two types of hierarchical relationships between subsystems?
what are their UML notations? |
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Definition
1. layer A "depends on" layer B
2. layer A "calls" layer B
runtime relationship is dashed lines
compile time relationship is solid lines |
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Term
| what's opaque layering and transparent layering? |
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Definition
| opaque layering: each layer can only call operations from layer below |
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Term
| what's design goal for opaque layering? |
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Definition
| maintainability and flexibility |
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Term
| what's design goal for transparent layering? |
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Definition
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Term
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Definition
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Term
| what's difference between 3-layer and 3-tier architecture? |
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Definition
3-layer is a style
3-tire is an architecture |
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