UML (Unified Modeling Language)

UML, or Unified Modeling Language, is a standardized modeling language used in software engineering to visualize the design of a system. It provides a set of graphical notation techniques to create abstract models of specific systems, such as conceptual, specification, and implementation models. UML is not a programming language but tools can be used to generate code in various languages using UML diagrams.

Use-Case Modeling

• Use-case modeling views the system as a closed entity defined by its response to external inputs.
• Use-case descriptions are commonly presented in plain text, with UML's stick figure notation being a prevalent method.
• Comprehensive understanding requires both textual and visual representations of use-cases.
• A use-case model encapsulates the system's functionality from a use-case perspective, often composed of multiple diagrams.
• A use-case diagram visually depicts the system, actors, use-cases, and their interconnections.

Components of Use-Case Model

1. Actors: Entities that interact with the system. Someone or something that uses our system to acheive a goal.Actors are need to be placed outside the system as they are the external objects.

   • Person
   • Organization
   • Another System
   • An external device

2. Use Cases: Specific ways that actors interact with the system. Each use case represents a specific functionality of the system from the actor's perspective. It performs the tasks within the system. Should be started with verbs.

3. Relationships: Connections between actors and use cases, or between different use cases. They represent the interactions and dependencies between different parts of the system.

• Association Relationships: A relationship between an actor and a use case. It represents the communication between the actor and the use case.

• Generalization Relationships: A relationship between two use cases. It represents the inheritance between the two use cases.

  

• Include Relationships: A relationship between two use cases. It represents the inclusion of one use case in another use case.

• Extend Relationships: A relationship between two use cases. It represents the extension of one use case by another use case. Photo Courtesy: Lucid Software-YouTube Channel

4. System Boundary: The scope of the system being modeled. It defines what is inside the system (i.e., the use cases) and what is outside the system (i.e., the actors).
   • Website
   • Software component
   • Business process
   • App

Creating Use-Case Diagrams

• Lucid: Lucid
• Drawio: Draw.io
• Adding an extension of drawio to the VS Code and naming the projects with the extesion ".drawio". It will open the drawio editor in the VS Code itself.

Watch the Tutorial

Everything You need to know about UML Use Case Diagrams

Happy Journey!