How to Draw Component Diagram in UML

How to draw component diagram in UML

Since they're capable of modeling hardware, component diagrams are an especially valuable UML sub-type. You can create simple UML component diagrams with Lucidchart, our cloud-based diagramming program.

Lucidchart is equipped with nearly every UML shape you might need. You can also import SVG, JPG, PNG, and Visio stencil files for greater flexibility. Try it free today!

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How to Create Component Diagrams

Component diagrams can be complicated, so it's important to understand the basics of UML diagramming. Try reviewing our component diagram tutorial, along with this guide on UML basics. That way, you'll have a firm grasp on the underlying principles of UML and component diagrams.



UML diagrams range from simple to complex, so you're probably looking for a flexible tool that can accommodate many use cases. Pen and paper diagrams or whiteboard drawings can be helpful when you're sketching out a rough outline, but they're hard to edit and share. We recommend a full-featured computer program like Lucidchart, which can help you build all sorts of charts. The instructions below are easily applied to Lucidchart and other applications.

Lucidchart lets you create a robust UML diagram without any special training. Real-time collaboration and digital publishing requires just a few clicks, so it's easy to receive feedback from colleagues, clients, or classmates.

How to draw component diagram in UML
How to draw component diagram in UML
How to draw component diagram in UML



Begin by creating a new document in Lucidchart. To create a customized view in the editor, select “More Shapes” and turn on your preferred shape libraries. This tutorial will use symbols from the UML shape library and its component diagram section. In Lucidchart, you can add shapes from the toolbox to the canvas by dragging and dropping. Repeat that action to adjust the position of each element.

Component diagrams center around the component shape, which is clearly labeled in the toolbox. Drag it onto the canvas, then click and type to add a label. Lucidchart allows you to resize all of its shapes, as well as add any needed styling from the dock on the right and the properties bar on top.

How to draw component diagram in UML


Contine adding component shapes until each major functional unit in your system or application is fully represented. It's helpful to break down components into their most granular groupings, in order to easily rearrange, understand, and update the document at a later time. Since all component diagrams consist of larger and smaller groupings, it's fine to nest components inside a frame, package, or larger component shape.

How to draw component diagram in UML



Add interfaces to each component, either with written notes or symbols. An interface models the what and how of input and output. For example, a component may receive information from another component or deliver services to an end user. Interfaces show how that process occurs; they can also help your team see any problems that were previously overlooked.

UML notation allows for two ways to list provided and required interfaces: through a secondary compartment in a component shape, or via lollipop and socket symbols that lead to and from the component. Lollipop shapes represent provided interfaces and socket symbols model required interfaces. If you opt to draw these symbols, you should use them in conjunction with dependency arrows (which are used in notation for many UML charts, like class and deployment diagrams.) To indicate dependencies—situations where one component or node is dependent on another—draw a dashed line that ends in an arrow.


It may be necessary to supplement component with ports, which show a distinct interaction point between the component and its environment. Ports are represented as small squares on the side of a component shape. You can add labels to each port by dragging out a text shape and typing inside it. Components and ports—along with other elements in the diagram—may be connected with dependencies and a few more interface symbols, if needed.


Round out your chart by adding nodes that are present in the system or application being modeled. These look like three-dimensional boxes and are meant to represent computational resources—including PCs, printing devices, and servers—that execute commands from UML artifacts.



Congratulations—you've created your first draft of a component diagram! Before you share it with the world, it's wise to ask a friend or colleague to check it for inaccuracies or inefficiencies. Then take a final look at the document yourself.

Lucidchart's features are constantly evolving to keep pace with industry standards. To see which UML shapes are currently offered, sign up for free and explore the product.

How to draw component diagram in UML

Lucidchart can help you create UML diagrams for work or school. Our cloud-based software works on any platform, so users can access Lucidchart anywhere, any time. Try it and see for yourself!

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