Sequence Diagram vs Communication Diagram
“What is the difference between UML Sequence Diagram and Communication Diagram? Are they the same thing?”
Some people think that they are the same diagram because they both display the relationship between objects, but actually they are different UML diagram and serve very different purposes.
Before we start, let’s take a look at the two diagrams first.
The two UML diagrams are created with the best UML software — Visual Paradigm. Visual Paradigm is an award winning modeling software. It supports a wide range of model and diagram types, such as UML, BPMN, ArchiMate, ERD, SysML, MindMap, PERT, SWOT, etc.
So let’s go back to the comparison between Sequence Diagram and Communication Diagram.
Both sequence and communication diagram are behavioral diagram types of UML. They both contains objects (or sometimes known as lifelines), but they have different focuses.
Sequence diagram focuses on the method invocations among objects under a particular scenario. In a sequence diagram you know what and when methods are called.
Communication diagram focuses primarily on the existence and occurrences of communication among objects. By reading a communication diagram you can easily identify if two objects are related with each other. Although communication diagram also contains objects and messages as a sequence diagram does, the methods involved in communication is only secondary information.
Some UML modeling software supports the synchronization between sequence diagram and communication diagram. Visual Paradigm does it best.
