UML use case extend relationship is used to show how and when some optional extending use case can be inserted into extended (base) use case.

UML use case extend relationship is used to show how and when some optional extending use case can be inserted into extended (base) use case. For example, Registration use case could be extended with optional Get Help On Registration use case.

Structuring Use Cases with Base, Include, and Extend: A Guide for

Here are the Use Case Diagram Guidelines You Need to Know

uml - Use Case Diagrams. Include - Software Engineering Stack Exchange

Extend and include in the UML use case diagram

UML Use Case Diagrams: Tips

What are Include and Extend Relationships in a Use Case Diagram

Use Case Diagrams

What Is Use Case?, Why Needed? And How To Make It? - All You Need

Concept: Use-Case Model

An example change case in a partial banking service use case model

Extension Point - an overview

uml - Specialization or extension point use case - Stack Overflow

uml - Can the included/extended use-case be initiated by another

What is the difference between extend and include functions in a