UML State Machine Diagram Notations, Examples and Tutorial

Last updated on July 19, 2021 by

State machine diagram is a type of chart that shows the transitions of various states from one to another. Mainly used in computer science and similar fields to visualize the transition process of a state. By observing these changes, one will determine if things are working as they should or if something is out of place. To further understand how this diagram works, we prepared some examples that you can refer to. We will also explain the components that make up this kind of diagram.

UML State Machine Diagram Tutorial

State Machine Diagram Components

A UML State machine diagram is basically open for any type of shape and elements. However, there are also symbols that you will commonly encounter here and most of them has a meaning behind it. On that note, here are some of the most common symbols that a state diagram has.

uml state machine components
  • Choice Pseudostate – Represented by a “Diamond,” choice pseudostate is used to indicate complex conditions with various potential outcome.
  • Event – Events are usually put into words above the arrow that represents the transition. In simple words, it is the trigger that caused the shift in the state.
  • Exit point – This is usually represented by a circle with an X mark on it. It is used if there are situations where the process is not yet completed, but has to be skipped for other reasons.
  • First State – This is the first thing that you’ll see when reading a UML state machine chart. It is represented by a black circle with an arrow attached to it.
  • State – States are the main star of this type of diagram, hence its name. It is represented by a rectangle with curves corners.
  • Transition – This is the arrow that flows between states. This is the indicator that changes are happening within the system.
  • Terminator – The exact opposite of the First state, the terminator is a dark circle inside a ring.

State Machine Diagram Examples

There are many templates that are available on the internet. Among these are thousands of State machine diagram that you can use for free. There are a lot of scenarios where you can utilize this type of diagram, and some of them are below. Check out the templates below and use them as you like.

  • Airport Check-in State Machine Diagram Template
airport state machine diagram
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One of the most busy places in the world are airports. Time of utmost importance here since a slight delay can cause inconvenience to many people. This is due to the influx of passengers on a regular basis that there should be no room for mistakes. On that note, a state machine diagram is really useful in processing passengers since it can streamline the process that they need to go through. It also eliminates redundant and unnecessary procedures to save a lot of time.

  • Calendar Scheduling State Diagram Template
calendar uml state machine chart
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Personal calendars these days are very important, especially for busybodies. This is due to their convenient features like automated scheduling, and alarm features. With that being said, the template above shows the process it takes for checking the availability of a date. This template is usable for free, and you can even make changes accordingly if you wish. To download the Calendar UML state machine diagram, click the button above.

  • Coffee Machine State Diagram Template
coffee uml state machine diagram
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The next template that we have demonstrates the state process of a coffee machine. From the moment that you turn on the machine, until you take your first sip there are states that happened and changed. Download the template above by clicking the button.

How to Make a State Machine Diagram

Although using templates is trendy these days, it is still important to learn how to make your own diagram. This is useful when editing and when state machine diagram templates aren’t available. Making one these days is a lot easier because there are many online tools that automates chart making. One example of these tools is GitMind. With that being said, we will teach you how to make one using this app.

  • Launch GitMind from your web-browser, and then click the “Try it online” button. After that, click the “New Flowchart” button from the landing page and the editing panel will appear.
open gitmind
  • Start editing the UML state machine chart by clicking the “UML” options from the left-hand side of the screen. Repeat the process until you complete the diagram.
edit uml state machine diagram
  • Once done editing, you can immediately download the chart on your PC by clicking the “Export” button and choose your preferred format. Aside from that, you can send the chart via URL to your friends by clicking the “Share” button.
share uml state machine diagram


State diagrams are without a doubt one of the most important charts made by man. This is due to its accuracy that all of us enjoy services and products that are not easy to make or recreate. On that note, if you are a student or an employee working with computer science or related field, then you will come across UML state machine diagram one way or the other. When that time comes, you can download the templates above. Alternatively, you can follow the steps that we provided to make one from scratch.

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Posted by: on to Tips and Resources. Last updated on July 19, 2021

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