(software) design: an analogy with my closet
DESCRIPTION
Advanced Software Engineering course (2014-2015): these slides show an analogy between the design of shelves for a closet, and the need ot software designTRANSCRIPT
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Advanced Software EngineeringURL: http://lore.com/Advanced-Software-Engineering-Univaq/
L01: (Software) Design: an analogy with my Closet!
Henry Muccini [email protected]
DISIMDep.nt of Information Engineering, Computer Science and MathematicsUniversity of L’Aquila, Italy
SEA Group
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The material in these slides may be freely reproduced and distributed, partially or totally, as far as an explicit reference or acknowledge to the material author is preserved.
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Software Development you are used so far….
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Software Design you may be used so far…
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A difficult lesson to teach
Why do we need to Design our Software
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Let me use an analogy…
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My closet
Drawing my closet
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First Design Question
Shall I buy a pre-made shelf?Shall I make it?
That translates into:«Shall I buy the system from the market, or buy some components and assemble the system I need!»
Many factors to be analyzed to make such a
decisionDiscussion
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Second Design Question
Which type of construction design pattern shall I use?
Discussion
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Important «Environmental» Constraints
Room Dimension
Room Characteristics Two no-nail walls!! Take into account the skirtings No-nail ceiling!!! Antenna cable
«The system and the enterprise provide environments for, and constraints on , the software
architecture» [SAinPractice_Book]
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Requirements
Build a stable, no crashing, structure Build shelves that can keep up to 40 kilos Cost = 0 (derived requirement)
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The initial design
Drawing the closet design
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Resources
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Other Resources
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Some further design decisions - RISK
How to build the «central» element?
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Some further design decisions - RISK
How to make this central element as stable as possible??
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Incremental implementation….
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Initial big mistake
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Fix to this mistake
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Fix to this mistake
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Hestetic Mistakes
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Documentation mistake
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Final Version
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From my closet to… Software Design
Buy vs. Build
Design Patterns
Design Decisions
Environmental Constraints
Risk mitigation
Incremental design
Resources
mistakes -> learn -> fix -> mistakes ->