acs2913 software requirements analysis and design · acs2913 software requirements analysis and...
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ACS2913 Software Requirements Analysis and Design Instructor: Victor Balogun
EXTENDED REQUIREMENTS MODELING
THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2019 1
Chapter OutlineUse Case Descriptions
Activity Diagrams for Use Cases
The System Sequence Diagram—Identifying Inputs and Outputs
SSD Notation
Use Cases and CRUD
Integrating Requirements Models
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Overview
Previous chapters identified and modeled the two primary aspects of functional requirements: use cases and domain classes
This chapter focuses on detail modelling for use cases to document the internal steps within a use case
Fully developed use case descriptions provide information about each use case, including:◦ actors, ◦ stakeholders, ◦ preconditions, ◦ post conditions, ◦ the flow of activities and ◦ exceptions conditions
Activity diagrams can also be used to show the flow of activities for a use case
Systems Analysis and Design in a Changing World, 7th edition – Chapter 5 ©2016. Cengage Learning. All rights reserved.
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Use Case Descriptions
Write a brief description as shown in Chapter 3 for most use cases.
Systems Analysis and Design in a Changing World, 7th edition – Chapter 5 ©2016. Cengage Learning. All rights reserved.
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Brief Use Case DescriptionsA brief description can be used for very simple use cases, ◦ system to be developed is a small, well-understood application.
A simple use case would normally have a single scenario and very few—if any—exception conditions.
A brief description does not document the internal processing since for simple use cases there are few steps.
THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2017 5
Use Case Descriptions
Write a fully developed use case description for more complex use cases
Typical use case description templates include:
1. Use case name2. Scenario (if needed)3. Triggering event4. Brief description5. Actors6. Related use cases (<<includes>>)7. Stakeholders8. Preconditions9. Postconditions10. Flow of activities11. Exception conditions
Systems Analysis and Design in a Changing World, 7th edition – Chapter 5 ©2016. Cengage Learning. All rights reserved.
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SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Fully Developed Use Case Description
Use case: Create customer account
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Fully Developed Use Case Description Create customer account (part 1 )
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Fully Developed Use Case Description Create customer account (part 2 )
Use Case Description DetailsUse case name◦ Verb-noun
Scenario (if needed)◦ A use case can have more than one scenario (special case or
more specific path)
Triggering event◦ Based on event decomposition technique
Brief description◦ Written previously when use case was identified
Actors◦ One or more users from use case diagrams
Systems Analysis and Design in a Changing World, 7th edition – Chapter 5 ©2016. Cengage Learning. All rights reserved.
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Use Case Description DetailsRelated use cases <<includes>>◦ If one use case invokes or includes another
Stakeholders◦ Anyone with an interest in the use case
Preconditions◦ What must be true before the use case begins
Post conditions◦ What must be true when the use case is completed◦ Use for planning test case expected results
Flow of activities◦ The activities that go on between actor and the system
◦ Usually the flow of activities is the most difficult part to develop, but also assists the analyst and the user to understand the requirements more deeply.
Exception conditions◦ Where and what can go wrong
Systems Analysis and Design in a Changing World, 7th edition – Chapter 5 ©2016. Cengage Learning. All rights reserved.
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SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Another Fully Developed Use Case Description Example
Use caseShip items
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Fully Developed Use Case Description Ship items (part 1 )
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Fully Developed Use Case Description Ship items (part 2 )
Activity Diagrams for Use CasesActivity diagrams were introduced earlier as a technique for documenting user workflows.
They are easily understood diagram to document the workflows of the business processes.◦ Here we will used them to model processing as well.
Activity diagrams are also an effective technique to document the flow of activities within a use case◦ They are are helpful when the flow of activities for a use case is complex
THE UNIVERSITY OF WINNIPEG - ACS 2913 - FALL 2017 15
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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UML Activity Diagram for Use Case
Create Customer Account
Note: this shows flow of activities only
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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Activity Diagram for Ship Items Use Case
Note:◦ Synchronization bar for
loop◦ Decision diamond
SYSTEMS ANALYSIS AND DESIGN IN A CHANGING WORLD, 7TH EDITION – CHAPTER 5 ©2016. CENGAGE LEARNING. ALL RIGHTS RESERVED.
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UML Activity Diagram for Use Case
Fill shopping cart
Note: this shows use case with <<includes>> relationship
Summary
Systems Analysis and Design in a Changing World, 7th edition – Chapter 5 ©2016. Cengage Learning. All rights reserved.
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This chapter focuses on models to provide details of use cases
Fully developed use case descriptions provide information about each use case, including actors, stakeholders, preconditions, post conditions, the flow of activities and exceptions conditions
Activity diagrams (first shown in Chapter 2) can also be used to show the flow of activities for a use case