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Supplementary SpecificationsSupplementary Specifications(Chapters 20,22 - Requirements Text)(Chapters 20,22 - Requirements Text)
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OutlineOutline
Refining the System Definition◦ A More Rigorous Look at Requirements◦ Supplementary Specifications
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System BehaviorSystem Behavior
Inputs Outputs Functions System Attributes Environmental Attributes
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What What NotNot to Put in Requirements to Put in Requirements
Project Planning Information◦ May be part of the contract, though
Design Information “what vs. how” Is this a requirement?
“This report will be prepared using visual basic crystal reports software”
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Requirements versus DesignRequirements versus Design
Requirements comes before design Users make requirement decisions while developers
make design decisions Does this model always work?
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RequirementsRequirements
Three types◦ Functional
◦ Non-functional (Quality attributes)
◦ Design The two important components that we will use are
◦ Use Case Model
◦ Supplementary Specifications
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Typical Nonfunctional RequirementsTypical Nonfunctional Requirements
These are the ones Leffingwell & Widrig detail: Usability◦ Ease of use
◦ Bill of rights Reliability◦ System availability
Performance◦ Response time
Supportability
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We’ll add a couple more of these…
From Bass, et al’s architecture book, which we use in CSSE 374 and 377:
Usability Availability
◦ Similar to Reliability Performance Modifiability
◦ Similar to Supportability Security
◦ New! Testability
◦ New!
Design ConstraintsDesign Constraints
Restriction of design options (e.g. what database to use)
Process (e.g. must use ISO or IEEE software engineering standards)
Regulations (e.g. FDA) Why are these in the requirements, if they involve
design?.
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Supplementary Specifications DocumentSupplementary Specifications Document
Includes◦ Nonfunctional Requirements,
◦ Design Constraints, and
◦ Other Requirements That are not confined to just one use case Leffingwell & Widrig’s template is available on Page
268/Appendix D We added some specific detail to the Quality
Attributes specs, in your version out on Week 4, Day 1
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How do you ”detail” a quality attribute?
Do “Scenarios” in which they typically would apply Similar to, but not the same as Use Cases for
functionality These Scenarios make it easier to see what to shoot for
in meeting these requirements, like:◦ How to design and implement for them
◦ How to test them in acceptance tests
What do the Quality Attribute Scenarios look like?
Source of stimulus: Stimulus: Environment: Artifact: Response: Response measure: