What is a Sequence Diagram?
A sequence diagram is a Unified Modeling Language (UML) diagram detail how operations are carried out. Sometimes it is called event diagrams or event scenarios.
Sequence diagrams consist of objects and the messages they exchange over time. This way, they are able to capture and visualize the nature and order of collaboration between objects over time.
There is a variety of messages can be used in sequence diagrams:
- Synchronous Message (requires a response before the interaction can continue)
- Asynchronous Message (don’t need a reply for interaction to continue)
- Reply & return message
- Self Message (message an object sends to itself)
- Create Message (message that can create a new object).
- Delete Message (message that can destroy)
- Found Message (message sent from an unknown recipient)
- Lost Message (message sent to an unknown recipient)
The sequence diagram benefits
Sequence diagrams are commonly used by IT developers to understand requirements for a new system or to document an existing process.