2 3 moving from blastoff to writing requirements: understanding the work
TRANSCRIPT
Lecture 5Ch. 4: Business Use Cases
SE3821 Software Requirements and SpecificationDr. Rob Hasker (based on slides by Dr. Brad Dennis)
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Today’s Outline• Business Events• Business Use Cases• Product Use Cases• Actors• Use Case Diagrams
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The Volere Process
• Moving from blastoff to writing requirements: understanding the work
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What are business events?• A thing that happens that makes your business respond in some way.• They can happen the moment an adjacent system
decides to do something (inbound).• They can happen when some processing condition
occurs (outbound). • They can happen on some schedule (time-
triggered).• They have inputs, outputs, and often both.
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Styleup Business Events
The work of tailoring weather
appropriate fashion advice.
Weather Forecast Service
Advertisers
Fashion Advisors
CustomerSubscribes
Profile
Fashionrecommendation
Weather
Places ads
Ad data
Fashion advice
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Styleup Business Event Table
Business Event Input Output
Customer subscribes Name and credit card Receipt
Customer adds profile
Customer meta data Confirmation
Weather forecast Forecast data
Advertiser places ads Ad content Acknowledgement
Ad data Report
Fashion advisor advises
Fashion advice
Work sends recommendation
Fashion advice
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How do we respond to Business Events?• This is the Business Use Case (BUC).• You should consider what the work does and what the
adjacent system wants or needs.
Customer
Advising
Stored DataReportin
g
Stored Data
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How do we respond to Business Events?• This is the Business Use Case (BUC).• You should consider what the work does and what the
adjacent system wants or needs.
Customer
Advising
Stored DataReportin
g
Stored Data
work boundary
the work
adjacent system/user/client
event
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What are some advantages of BUCs?• A BUC is a whole, self-contained response.
• It only interacts with other BUC’s via stored data.
• This provides a nice, cohesive way to begin to partition the work.• They are chunks of work that are recognizable to stakeholders.• A BUC happens in a discrete time frame.
• Once triggered, it runs to completion.
• It may aid in identifying more stakeholders, such as SME’s.• We’ve made no assumptions about the product.
• We are modeling what the work is and not missing potentially important aspects.
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Business Use Case Exercise
• Regroup with your partners from Lab 1• Spend the next 10 minutes and model one Business Use
Case for a Business Event from your earlier exercise.
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What’s a product use case?• The portion of the BUC that the product will handle.
Consider a scope that best contributes to the BUC work.
Customer
Advising
Stored DataReportin
g
Stored Data
The PUC
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Why not just focus on the product?• Why do we have business use cases, product use
cases?• Key issue: identifying a useful scope• Focus on product: key issues in ripping music from CD are
formats, bit rates, letting user name the song• But consumer interested in building a music collection
• Important tool: stepping back• Examine scope, look for broader needs
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How does this map to a use case diagram?• A use case is a chunk of functionality that describes
the interaction between a user and a system.
Customer
Advising
Stored DataReportin
g
Stored Data
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How does this map to a use case diagram?• A use case is a chunk of functionality that describes
the interaction between a user and a system.
Customer
Advising
Stored DataReportin
g
Stored Data
Use case diagram
Actors
An actor is person or system that interacts with the system under development.
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UML Use Case Diagrams• UML Use Case Elements
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Styleup-Advisor PUC Diagram
Generate Fashion Advice
Reporter
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Styleup BUC?• UML Use Case Diagram doesn’t have notation for a
data store, so it isn’t suitable for modeling a BUC. BPMN 2.0 is a feature rich language.
Fashion AdviceStart
Evaluate profile and forecast and
generate advice
Profiles, forecasts, advice
advice ready Reporting Process
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Group Exercise
• Regroup with your partners from Lab 1• For the remainder of the class produce a Business Event
table for your Lab 1 scenario. Select one business event and model a BUC. For some portion of that BUC, develop a PUC. You may use the Work Context Diagram generated in Lecture 4. Be prepared to share highlights of the exercise.
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Next Meeting• Lecture 6 – Investigating the Work• Read Chapter 5