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Creating a UML diagram: How-tos, templates, and tips

Learn the definition of a UML diagram, its different types, and the notations they use. Get started on visualizing your systems in a UML diagram online using our guide and templates.
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What is a UML diagram?

UML diagrams are the representation of the UML notation. It consists of standard elements (such as components, classes, and use cases) that are connected using relationships(opens in a new tab or window) (arrows) to represent the architecture, implementation, and structure of an otherwise complex software system.

A simple example of a UML diagram showing the relationships between different actions.

A simple example of a UML diagram showing the relationships between different actions.

UML diagrams most often visualize the following:

  • Components of the system and how they interact with other components
  • The user interface of the system
  • Activities or jobs carried out by the components or interfaces
  • How different entities interact with components and interfaces
  • How the system runs

A UML diagram differs from a UML model, which is the abstract representation of a system. It consists of a combination of different types of UML diagrams and some additional documentation.

Simply put, UML diagrams are the actual representation of the UML language, and one or more UML diagrams make up the UML model.

What is UML?

Unified modeling language (UML), as the name suggests, is a modeling language used to visualize the design of various software and business systems. It uses standard notations for specific processes and participants, making it an ideal modeling language that can be understood universally.

An important distinction to note: UML is not a programming language like Java or C++. These programming languages build systems through code, whereas UML visualizes them like a map. However, through the use of tools, code can still be produced from UML diagrams.

A brief history of UML diagrams

The UML notation was originally created to standardize approaches to software engineering. Developed in 1994-1995, it was adopted by the Object Management Group (OMG) and was accepted as an ISO standard(opens in a new tab or window) in 2005.

UML finds its roots in object-oriented programming(opens in a new tab or window) methods but has slowly extended to other forms of design documentation in business modeling practices, for example. The current version of UML is UML 2.4, and it is continually updated to include fixes to any issues.


Why use UML diagrams?

The widespread adoption and increased usage of UML diagram-maker tools beg the question: What are the benefits of UML diagrams and what are UML diagrams used for?

Typically used in software development, UML diagrams have also found their way to business modeling practices. They offer the benefits of improved communication, collaboration, and system understanding.

Canva has various UML diagram templates you can customize according to your needs.

Canva has various UML diagram templates you can customize according to your needs.

Enhanced visual communication and collaboration

UML diagrams (such as component diagrams and structure diagrams) make it easier for technical and non-technical audiences alike to visually understand the overall architecture of a system. It’s a great complement to system documentation that also simplifies complex structures, thereby enhancing communication, and collaboration.

Popularity

UML is one of the most used tools for visual software design. It has emerged as a standard notation to communicate system and software designs, and its widespread use ensures that it is well understood by most software-related professionals.

Flexibility

UML diagrams can also be customized according to your specific needs. You can modify interactions and modeling elements, create new stereotypes and constraints, and use them not just for software development, but also for most business modeling needs.

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Canva for Teams
Store your UML diagram in your team folder in Canva so that various technical and non-technical teams in your organization can easily refer to them and keep themselves in the loop.
Preview of real-time collaboration when you make a UML diagram in our Canva Whiteboard. Together, customize and edit your diagram accordingly.

Preview of real-time collaboration when you make a UML diagram in our Canva Whiteboard. Together, customize and edit your diagram accordingly.

Fraction of learning

While there are over 14 types of UML diagrams, popular ones like the class diagram, use case diagram, structure diagram, and behavioral diagram are the only ones most professionals really need to be aware of. This means that with even just 20% knowledge of the UML language, you can already effectively communicate what you need to.

An abundance of free UML diagram tools

UML diagrams are now more accessible and easier to make thanks to the many UML diagram creator tools available online. With a simple search, you can find anything from free UML software (with simple templates) to paid bespoke solutions (which can generate code from design, reverse engineer code, perform analysis of software solutions, and even mine requirements).


What are the different UML diagram types?

A combination of UML diagrams makes up the UML model. The 14 types of UML diagrams represent the UML model either structurally or behaviorally, as will be discussed below.

Structural UML diagrams

UML structural diagrams represent the static structure of a system. These diagrams use objects, operations, relationships, and attributes to analyze or depict this structure. Under structural UML diagrams are the following types:

There are seven types of diagrams under UML structural diagrams.

There are seven types of diagrams under UML structural diagrams.

Behavioral UML diagrams

UML behavioral diagrams represent the behavioral view of the system. These diagrams showcase collaborations between objects, and the states of objects to describe the behavior of the system within itself and with other entities. Below are the different types of behavioral UML diagrams:


How to make a UML diagram

Despite the myriad of benefits offered, creating a UML diagram still requires a well-thought-out process. How to draw UML diagrams that can effectively represent your system? Read on to find out.

How to make a UML diagram

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Plan with a team
Choosing which UML diagram to use is crucial, so you’ll want as many perspectives as possible to weigh in on important decisions. They can also provide info that you may otherwise not have.


Get inspired with UML diagram templates

Comprehend and stay on top of your system by plotting it down in a UML diagram. Whether you’re building software or streamlining your business workflow, our UML diagram examples can be tailored to fit what you need. With your team, select a template below and get started on your design.


All you need in a UML diagram maker

Build your diagram like clockwork. Connect your classes, objects, and other elements together using our suite of easy-to-use whiteboard tools and stunning design elements. Your shareable whiteboard has infinite space, so you can account for all of the elements of your system.

  • Unlimited space for unlimited ideas

    Unlimited space for unlimited ideas

    With a free infinite canvas and unlimited number of whiteboards, fully develop your ideas and still have room.

  • Your ideas visualized

    Your ideas visualized

    Build stunning tables and graphs with automatic flowcharts, or sketch them to life with Draw.

  • All your work, in one place

    All your work, in one place

    From plan to execution, it’s all here. Take notes, brainstorm, collaborate, and more on the same whiteboard.

  • Workshop ideas to perfection

    Workshop ideas to perfection

    With your team, develop ideas through comments and stickies, and keep sync sessions on track with a timer.

  • Share your work effortlessly

    Share your work effortlessly

    Share a link to your doc and control your team's access. Present directly from the editor with Presenter view.

  • Expand your Presentation to a Whiteboard

    Expand your Presentation to a Whiteboard

    With just a single click, expand your presentation slides into infinite, collaborative whiteboards.


UML diagram best practices

Building a good UML diagram means doing practices that ensure the result is clear, understandable, and on par with standard notations and formats. With that said, it helps to consider the following when you make your UML diagram:

Less is more

Large, complex diagrams confuse more and convey less. Here are some practices you can adopt to avoid unnecessary complexity by making your diagram as simple and concise as possible.

  • Don't overload the diagram with too many elements and relationships.
  • Use clear notations and readable fonts.
  • Avoid using long names for elements.
  • Avoid too many references to external information.
  • Prevent the use of multiple colors and multiple fonts in the same diagram.

Abstract and decompose your diagram

Break down large and complex diagrams into smaller, simpler, and understandable parts. Decomposition is the process of dividing a complex system into subsystems, classes, or components with well-defined interfaces. Abstraction is the process of reducing the amount of low-level, unnecessary details and displaying only the required high-level ones. Using these techniques can help make your diagram more understandable, modular, and manageable.

Organize with layers

You can also make complex UML diagrams easier to understand by using layers or by grouping elements. With layers, you can show specific levels of detail, without compromising the bigger picture.

Organize your elements into layers, which you can lock or position according to your preference.

Organize your elements into layers, which you can lock or position according to your preference.

Insert profiles and stereotypes

Not all system domains are the same. You can use stereotypes and profiles to extend UML notation to suit your specific domain. Representing your system in your way and defining new elements can help you make your UML diagram easier to understand in your context.

Use a UML diagram maker tool

Instead of starting a diagram from scratch, use a UML diagram generator tool to ease your drawing process. A tool offers the benefits of simulation, validation, verification, and reverse engineering, all of which can help make your diagram more consistent, concise, and easy to comprehend.

A good UML diagram creator should contain the following features:

  • An easy-to-use and intuitive interface.
  • A large surface area to work on, such as a whiteboard.
  • The support of different types of UML diagrams, specifically the more popular ones (use case diagrams, activity diagrams, class diagrams, and sequence diagrams).
  • Real-time collaboration, which allows problems to be weeded out during the design process.
  • A large library of UML symbols, shapes, pictures, animations, icons, and elements to choose from.
  • Drag-and-drop tools to move components into the design.
  • Easy customization of appearance.
  • A change tracking and version control system to easily revert to previous versions.
  • Export options in different formats for easy shareability.
  • Adequate support and documentation to turn to in case of issues.
  • Affordable pricing plans and licensing options.
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Create UML diagrams with Canva
Canva Whiteboards has the free design elements and tools you need to create a UML diagram that’s not only fully comprehensive, but also shareable with teams.

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