Communication diagram

What is a Communication diagram?


What is a Communication diagram?

Symbols and notations of  diagrams

Basic components of the  diagram

Example of a diagram with description.

Sequence diagram advantages over communication diagram?


Communication diagram examples Diagram

Communication diagram

This diagram is formerly known as a collaboration diagram. This diagram is similar to the sequence diagram in UML. The main focus of this diagram remains on relationships of objects.

This diagram offers the same information as sequence diagram. There is a slight difference between these two. The sequence diagram emphasizes the messages exchanged between objects. This diagram offers a broader perspective within a process. Free UML software is available to draw this kind of diagrams.

Basic components of a communication diagram

These diagrams are similar to sequence diagrams. But these diagrams offer even better understanding. It gives more understanding of components communication and their interaction with each other. These diagrams are useful for businesses, organizations, and engineers to visualize physical communication within a program.

To try drawing a sequence diagram:

  • We have to model the logic of the entire procedure, functions, or operations.
  • We have to identify how commands are sent and how they are being received between the objects or the components of a process.
  • We also have to visualize the consequences of specific interactions between multiple co moments in a process.
  • We need to plan and understand the detailed functionality of an existing or future scenario.

Click below to read about: 

State Diagram

Symbols and notations of communication diagrams

  • The symbols and the notation for these diagrams are the same as of the sequence diagrams.
  • A rectangle represents an object. It makes up the application.
  • Lines between class instances are used to show the relationship between different parts of the application.
  • Arrows are used to represent the messages. Messages are sent between the objects.
  • To see the orders of the messages, numbers are used. It helps to know how many messages are sent and how many are still needed to finish the process.


Below is an easy example. This diagram explains the process of adding an event to a calendar. Almost in all the examples of this diagram, the exact commands and requests are shared between multiple steps in the process. The number on lines show the orders. They also represent the options in which they are activated. It is a fact that some actions happen concurrently. It is because of the use of letters.


Communication diagram


Sequence diagram advantages Vs communication diagram

  • Tool support is better.
  • More notation options are available.
  • It is easy to see a sequence.
  • It is a simple reading from top to bottom.
  • Where this diagram needs numbers to be read to understand the sequence.


Read more about:

Activity Diagram

Use Case Diagram