UML Communication Diagram

UML Communication Diagram Template

Get a complete snapshot of how every object in your program interacts with all the others.

About the UML Communication Diagram Template

Anybody who’s ever built a software-as-a-service product for a wide audience knows that communication is a huge part of development.

If you can diagram what parts of your product communicate with what other parts, at what times, and for what purposes, you’ll get a clear, holistic outline of its entire functionality.

That’s what a communication diagram template is for. As opposed to a sequence diagram, which looks at processing over time, a communication diagram gets you a big-picture snapshot.

It’s a lot like process mapping, but for programs instead of workflows.

Keep reading to learn about what to expect from our Communication Diagram template and how you can use it to improve your apps.

What is a UML communication diagram?

Think of a communication diagram as a complete map of your product.

A map shows distinct areas, places them in the correct positions relative to each other, and charts the roads that lead between them.

In the same way, a communication diagram (also called a collaboration diagram or interaction diagram) maps every object in your program and illustrates how they relate to each other.

Communication is the heart of software design. No matter what it’s ultimately for, a program accomplishes its goals by having different objects “talk” to one another. Even though a program doesn’t physically exist, a communication diagram can help you picture it.

The communication diagram is often confused with the sequence diagram, which is related but distinct. A sequence diagram emphasizes the flow of time through the system. It shows in what order a request is relayed from one object to another.

In other words, if a communication diagram is a map, a sequence diagram is more like a set of directions. It also paints a picture of the territory, but in a different way.

Benefits of a communication diagram

With a communication diagram, you can:

  • Clarify the role of each object in the program. If you forget what a certain page is doing in your web application, a quick glance at the communication diagram can remind you.

  • Diagram complex logic chains that involve multiple objects. Yes, you can write these out verbally. However, some people are visual learners and will comprehend the logic faster if it’s conveyed through a communication diagram.

  • Plan new functions and scenarios for the program. Once you’re comfortable with your communication diagram, you can use it to collaborate with your remote team on fitting new feature designs into the program.

  • Add new objects more easily than in a sequence diagram. A sequence diagram is usually filled end-to-end and lacks room to add in additional functions. The layout of a communication diagram is more growth-friendly.

Create your own communication diagram

Our Communication Diagram template gives you all the tools you need to create your own communication diagram and collaborate on it with your team. It’s an example of a UML (Unified Modeling Language) diagram, a set of diagrams that uses standardized imagery to convey ideas in a universal way.

To get started, simply select “Communication Diagram” from our template picker, then follow these steps:

Step 1: Decide what function(s) you want to model

Remember, a communication diagram is about getting a holistic snapshot of a feature or a whole product. Start by deciding what you want to model and what your goals are for this diagram.

Step 2: Create rectangles for each object involved in the function

Don’t let the blank canvas frighten you! Choose rectangles (or any other shape) from our shapes library, then label them as the objects that take part in the function you’re modeling.

Step 3: Connect the related objects with lines

Use Miro’s connection lines to link objects that communicate with one another. Don’t worry about direction for now. For this step, just define which objects are related and which ones aren’t.

Step 4: Use arrows to mark where one object sends a message to another

You can customize your connection lines to turn them into arrows. Using this feature, mark every location where one object talks to another — for example, a link that sends you to your login page.

Step 5: Label the arrows with numbers to denote the order messages are sent in

Customize your connection lines further to illustrate the steps of a multi-sequence process. You don’t have to get as detailed as you would in a sequence diagram, but you should add any information necessary to grasp the overall function.

Step 6: Continue adding new objects as needed

The communication diagram template makes it easy to keep adding new shapes and connection lines as often as you need.

Example of an effective communication diagram

Let’s run through an example of what a working communication diagram/collaboration diagram might look like. Imagine you’re building an app where users can purchase plane tickets.

First, define all your objects. The list might include:

  • Landing page

  • Login window

  • User profile

  • Search interface

  • Search results page

  • Purchasing window

  • Purchase confirmation

  • Email confirmation

Select shapes for all of them, and lay them out in the Miro template. Next, connect the objects that work directly with each other: the login window and profile, the search feature and results, the purchase flow, and so on.

When one object communicates with another, add an arrow. For example, the search interface and search results work in a loop, so each should have an arrow pointing at the other.

Finally, look for multi-step sequences, and add numbers to define how they work. The purchasing and payment flow is a common multi-step process.

Communication diagram FAQ

What is the use of a communication diagram?

A communication diagram helps you illustrate the inner working of a program by representing it as a series of connected shapes. At a glance, you can tell what objects make up the program, how they work together, and the general order of operations.

How do you draw a communication diagram?

It’s easy with Miro. Just select the Communication Diagram Template, add shapes from our shape library, and connect them with customizable connector lines.

What are the elements of a communication diagram?

A communication diagram is made up of shapes (representing objects), lines (representing relationships), arrows (representing one-way or two-way communication), and numbers (representing an order of operations).

How are sequence diagrams and communication diagrams different?

Sequence diagrams illustrate how a process unfolds over time, while communication diagrams focus on a broad snapshot of what’s happening in a single moment. Their functions overlap, but they aren’t identical.

UML Communication Diagram Template

Get started with this template right now.

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