How to Draw a UML Diagram with SmartDraw

SmartDraw is designed to help you create UML diagrams quickly and easily. You'll get ready-made templates and symbols as well as tools specifically designed to build the diagram you need.

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Finding the UML Symbols and Templates

SmartDraw has a number of UML templates located in the Software Design category under New Document on the Dashboard. To start drawing, simply open any of SmartDraw's UML templates. You can choose between:

  • UML Activity Diagram
  • UML Class Diagram
  • UML Communication Diagram
  • UML Component Diagram
  • UML Composite Diagram
  • UML Deployment Diagram
  • UML Interaction Diagram
  • UML Package Diagram
  • UML Sequence Diagram
  • UML State Diagram
  • UML Use Case Diagram
UML templates

Using the SmartPanel

Every UML template opens with a specialized UML SmartPanel docked to the left of the work area. This panel has a symbol library with the most common symbols for your chosen UML diagram. It also has tools that will help you build the diagram like selecting line options appropriate for that diagram type or even importing data.

UML SmartPanel

Adding UML Symbols to Your Diagram

You can add a symbol to your drawing by selecting it in the library and then dragging it to the page.

Once you already have a symbol on your diagram, you can add new ones by drawing lines. First, click on any of the yellow dots at the perimeter of a shape to start drawing a line. We call these Quick Action Controls. At the end of the line, you'll see a pop-up menu of symbols. Select one to add it to your diagram, connected to the previous shape.

This menu is pre-populated with the most common symbols for the selected diagram type. The options will change over time to symbols you use, so you'll always have what you need at your fingertips.

Add UML symbols

Defining Connections and Relationships with Arrowheads

Most UML diagrams involve connecting one or more shapes to each other using lines and using special symbols on these lines to indicate relationships.

As discussed above, you can easily build your entire UML diagram by drawing lines and adding shapes that are automatically connected to the previous shape.

Many UML diagrams use arrowheads at the end of the line to represent relationships like aggregation, dependency, inheritence, composition, and association for classes and interface type for components.

To show the relationship between classes for example in a UML Class diagram, select the line and choose the appropriate arrowhead and line style from one of the options under Class Line Style in the Lines subsection. Show aggregation, association, inheritance, and more.

Define class relationships using lines

In UML component diagrams, an interface (small circle or semi-circle on a stick) describes a group of operations used (required) or created (provided) by components. A full circle represents an interface created or provided by the component. A semi-circle represents a required interface, like a person's input.

With a line selected, you can easily apply the right kind of interface notation at the end of a line using the Interface Line Style in the Lines subsection.

Define interface line types

For other UML diagram types like Use Case and Activity, you can choose from the basic UML line and arrow styles in the Line Style drop-down.

Define line styles for other UML diagram types

Reverse Line Direction

You can reverse the arrows on a line by clicking the Reverse Direction command on the SmartPanel.

Reverse direction

Add Multiplicity

UML class diagrams often use a multiplicity notation to indicate the number of instances of one class linked to one instance of the other class. For example, one company will have one or more employees, but each employee works for just one company.

You can show multiplicity by selecting a line and clicking Add Multiplicities in the Lines subsection. This will put a placeholder multiplicity notation at both ends of the selected line.

Add multiplicities

Adding and Editing Text

To add text to a shape or a line, select it and start typing. Depending on the particular shape, your text will appear inside, below, or above the shape.

For a line, your text will appear centered on the line. Some shapes will already have text on them. To edit this text, double-click on the area you want to edit.

Change Text Style and Color
You can change font size, font type, and color in the Home tab. You can change text alignment in the Design tab.

To add text to your work area as an independent object, click on the Text tool at the top of the SmartPanel to the left of your workspace.

Editing text

Import Data to Create a Class Diagram

You can create a UML Class diagram automatically without any drawing at all by pointing SmartDraw at a code repository. You can either use Github or a local repository to import your Class data to generate a diagram.

Alternatively, you can also use the + or Plus menu to select the UML Class Diagram visualizer. Learn more about the UML Sequence Diagram visualizer.

Import class diagram data

Import PlantUML Markup from Lucidchart for Sequence Diagrams

You can import Lucidchart's PlantUML markup to generate a UML sequence diagram automatically.

Simply, click the Import Lucidchart UML command on the SmartPanel to the left of your workspace.

Alternatively, you can also use the + or Plus menu to select the UML Sequence Diagram visualizer. Learn more about the UML Sequence Diagram visualizer.

Import Lucidchart UML