![Modeling optional behavior with UML extension points and extend relationships - Support - Bizzdesign Support Modeling optional behavior with UML extension points and extend relationships - Support - Bizzdesign Support](https://support.bizzdesign.com/download/attachments/39814459/worddavc3662270d3b0ad8f190b97b5d9b0619b.png?version=1&modificationDate=1559903155576&api=v2)
Modeling optional behavior with UML extension points and extend relationships - Support - Bizzdesign Support
![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.](https://www.uml-diagrams.org/use-case-diagrams/use-case-extend-condition.png)
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.
![An example of UML use case diagram for a bank ATM (Automated Teller Machine) - Customer actor uses bank ATM to check balances, deposit funds, withdraw cash and to transfer funds. An example of UML use case diagram for a bank ATM (Automated Teller Machine) - Customer actor uses bank ATM to check balances, deposit funds, withdraw cash and to transfer funds.](https://www.uml-diagrams.org/examples/use-case-example-atm-transactions.png)