Use case diagram

As explained in Software Design for Python Programmers

A use case diagram is a UML behavioral diagram that represents an application's externally visible interactions through actors and use cases.

A use case diagram models an application's externally visible behavior by grouping user goals and showing which external actors interact with them. It gives requirements a runtime context and establishes the application's boundary. section 3.5 section 3.6

Build a diagram by identifying:

• The application boundary, drawn as a box containing the use cases. section 3.6.1
• Short, descriptive use-case names in verb–noun form, such as “Add Book” or “Log In Customer.” section 3.6.1
• Actors outside the application, including people, databases, or other systems. section 3.6.1
• Interaction lines connecting each actor to the use cases they can perform. section 3.6.1

Book catalogue

An advanced book catalogue diagram groups six use cases inside the application boundary and connects customers, librarians, and a backend database to their interactions. section 3.6.1

Figure 3.4 A UML use case diagram containing the names of six use cases for an advanced version of our book catalogue application. The labels in the dashed boxes and the dashed arrows indicate the various components of the diagram. When drawing a use case diagram, do not include these labels and arrows.

Use the figure to distinguish the boundary, actors, use cases, and interaction lines; omit its explanatory dashed labels when drawing. section 3.6.1

How Software Design for Python Programmers covers it

How deep it goes

Defines boundaries, actors, names, and interactions, while deferring detailed flows to separate use case descriptions.

Examples

Uses a book catalogue with customers, librarians, a database, and six named use cases.

What it assumes

Assumes application requirements and user goals, while defining actors, use cases, boundaries, and interaction lines.

What you can do after

Evaluate application scope and actor interactions through a compact visual requirements model.

How it connects

Connects requirements, use cases, actors, application boundaries, and use case descriptions.

liveBookmanning.com

Read Software Design for Python Programmers on liveBook Get the book at manning.com

Also explained in

• 

  liveBookmanning.com
  Functional Design and Architecture: Examples in HaskellA use case diagram is a requirements-modeling diagram that shows actors, the actions they trigger, and the context of those actions.

Compare how 2 books explain use case diagram →

Related concepts

• Unified Modeling Languagepart of · The Unified Modeling Language is a standardized visual modeling language for specifying, visualizing, constructing, and documenting software and other systems.
• use casehas part · A use case is a description of a situation or interaction in which a system, method, or capability is applied to achieve or support a goal or outcome.
• use case documentationpart of · Use case documentation is a collection of artifacts, including diagrams and written descriptions, that records an application's use cases.
• mind mapcontrasts with · A mind map is a visual diagram that organizes ideas and their relationships around a central topic through branching connections.
• functional specificationused by · A functional specification is a document describing a system’s externally observable purpose, capabilities, required behavior, requirements, and use cases without prescribing implementation details.

This explainer was generated by Manning's knowledge graph from the text of Software Design for Python Programmers. The section links point to the parts of the book it draws on.