Requirements Gathering Technique: Use Case Diagrams with Latinitas Project example

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Requirements Gathering Technique Use Case
Diagramswith Latinitas Project example

• By Gretel Paronzini-Fredette

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Agenda

• Use Case Definitions
• Value of Use Cases
• Brief Overview of Use Case Core Components and
  Structure
• New Approach for Gathering Latinitas
  Requirements
• Use Case Diagram vs. DFD
• Use Case Specification Login and Authenticate
• Tips on requirements gathering
• Questions

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Use Case Definitions

• Use Case Diagram
• Use Case Model
• Use Case Specification/ Definition/Des
  cription

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Use Case Definitions

• Use Case Model
• A view of a system that emphasizes the behavior
  as it appears to outside users. A use case model
  partitions system functionality into transactions
  use cases that are meaningful to users
  actors. There are two kinds 1- Use Case
  Diagrams, and 2- Use Case Descriptions (Kobryn)
• Use cases and use case diagrams are the Unified
  Modeling Language (UML) features that support the
  gathering and analysis of user-centric
  requirements by starting with your users goals.
  (Chonoles, Schardt)
• Use Case Diagrams Definition
• A use case diagram is a graphic representation
  of the key features of the written use case
  reports that comprise a system. (McLeod, Jordan)
• High-level visual representation of the user
  requirements. (Weigers)

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Value of Use Cases

• Use cases help the analyst focus on what the
  users need to accomplish vs. on what the users
  want the system to do.
• Use cases help focus on users goals. Thus, you
  can provide systems that deliver value to your
  customer.
• Use cases help the requirements analyst with the
  organization of requirements
• They allow descriptions of sequences of events
  for what the actor does with the system.
• They help with requirements prioritization. The
  highest priority functional requirements are
  those that originated in the top priority use
  cases.

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Value of Use Cases Part 2

• Use cases help bridge the gap between business
  requirements and the application of technology.
• Use cases are a road map for developers and
  testers. Programming code and test cases are
  traced back to each one of the functional
  requirements described in the use case
  descriptions.
• Use cases also allow the requirements analyst to
  discover business rules, and data exchanged
  between the actor and the system.
• Use case diagrams provide visibility to the
  system internals unlike the DFD and Context
  Diagram.

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Brief Overview of Use Case Core Components and
Structure
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Visio Software UML Options
Use Case Symbols
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Brief Overview of Use Case Core Components and
Structure Use Case Description

• Basic Structure and Components
• Use Case Name
• Brief Description
• Actors
• Pre-Conditions
• Post-Conditions
• Basic Flow
• Alternate Flows
• Exception Flows

• Additional Components
• Special Requirements
• Data Sources
• Dependencies
• Assumptions
• Open Issues
• It is advisable to keep data sources in the use
  case until they are signed off by the user. After
  that, it is recommended to have them in a data
  dictionary instead. (One place to make
  modifications)

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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas Requirements
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New Approach for Gathering Latinitas
Requirements Login and Authenticate UCS

• Latinitas - Login and Authenticate UCS.DOC

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Tips for requirements gathering

• Use as many tools as you need to understand your
  clients problems/needs.
• Ask questions, be a detective, perform your
  clients job.
• Find out what your clients business processes
  are.
• Find out functional and non-functional
  requirements, constraints, data to be used, and
  business rules.
• Document EVERYTHING!
• Encourage feedback from your client, make
  him/her be part of the requirements gathering
  process.
• Ask the client to sign-off requirements.

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Questions?
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Works Cited

• Chonoles, Michael J., and James A. Schardt. UML 2
  for Dummies. Hoboken Wiley, Inc., 2003.
• Kobryn, Cris. "Introduction to UML Structural
  and Use Case Modeling." Telogic. Object Modeling
  with OMG UML Tutorial Series. 2001. 1 Oct. 2007
  ltwww.omg.org/docs/omg/01-03-02.pptgt.
• McLeod Jr., Raymond, and Eleanor Jordan. Systems
  Development a Project Management Approach.
  Danvers John Wiley and Sons, 2002.
• Reinhold, Christiane. Personal interview. 5 Oct.
  2007.
• Steinle, Randy. "Use Cases." Systems Evolution.
  Educational Briefing. Department of Information
  Resources, Austin. 07 Dec. 2005.
• Weigers, Karl E. Software Requirements, Second
  Edition. Microsoft Press, 2003.

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