What Is a UML and What Are Its Benefits?

By Indeed Editorial Team

Published June 17, 2022

Visualization can be a helpful tool for many professionals who manage some part of a design process. The Unified Visual Language (UML) is a standard graphical notation for visual modelling using the object-oriented paradigm. Knowing about UML helps systems analysts, architects, programmers, and business analysts to model a system independently of any implementation language or technology. In this article, we answer the question "What is UML?", highlight its uses, explain who can use it, elaborate on how to use it, describe some major concepts, and give tips to help you make a diagram.

What is a UML?

The answer to the question "What is a UML?" involves understanding its purpose, uses, users, and structure. UML is a visual language that provides a way for software engineers and developers to construct, document, and visualize software systems. These visual representations help software developers better understand potential outcomes or errors in programs, saving time and enhancing collaboration among team members.

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What are the benefits of UML?

The following are some of the reasons why UML is beneficial for software developers:

Helps in communication

UML provides a standard language that communicates design information among software developers. This saves time and money, as it eliminates the requirement to train developers in a new, proprietary software language. It also facilitates communication with other teams or individuals who review the design.

Saves time

UML can help developers save time by automating some of the design processes. In addition, using this language can help developers avoid potential errors in their programs, which can save time in the development and testing processes. UML can also save time in the coding process because it allows developers to reuse code.

Enhances collaboration

UML allows different software developers to work on the same project by providing a common language. This enhances collaboration and provides for a more efficient design process. It also helps identify potential problems early in the design process.

Provides a better understanding of a system

UML allows developers to see the big picture of a system. This can help them understand the system better and identify potential challenges. It also allows them to see how different system parts interact with each other.

Unifies design

UML provides a standard way to design software and systems. This allows for a more unified design process and helps to ensure compliance with standards. It also offers easier design reviews and enhanced productivity.

What are the major concepts of UML?

UML provides the ability to create an object-oriented program, but it's important to understand object-oriented concepts before you do so. The following are some of the major concepts of object-oriented programming:

  • Objects: An object is a self-contained component containing data and behaviour. This helps represent real-world objects.

  • Classes: A class is a template for creating objects. It's a blueprint that defines the variables and the methods common to all objects of a certain kind.

  • Encapsulation: Encapsulation is hiding the details of an object from other objects. This allows for a more abstract view of the object, making it secure and easy to use.

  • Inheritance: Inheritance is creating a new class from an existing class. This allows for code reuse and makes adding new functionality to an existing class easier.

  • Polymorphism: Polymorphism is the ability of an object to take on different forms. Objects may change behaviour or appearance, but they maintain the same interface.

  • Abstraction: The abstraction visualizes the object's behaviour and its dependency on another diagram element. It allows developers to focus on the functionality of an object without considering its implementation details.

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Who uses UML?

Software developers, system analysts, business analysts, and project managers use UML. It's helpful in the design and development of software systems. It's also beneficial in the analysis and understanding of business processes. You can use UML in fields such as the following:

  • Health care

  • Telecommunications

  • Manufacturing

  • Government

  • Banking and finance

  • Retail

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How do developers use UML to improve software quality?

Software developers use UML to create successful models and designs for adequately functioning systems, which helps them reduce their efforts during the software development process. One significant benefit of using this language is determining workflow. After developers finish writing the code, they draw the diagrams to document different workflows and activities and delegate roles. This helps them make informed decisions and develop efficient systems. This language contains 13 types of diagrams that software developers and other professionals draw and use. These diagrams separate into two groups, which include the following:

Structural diagrams

Structural diagrams show a system's structure, implementation levels, and individual parts. They also show how these components interact to create a functional system. Here are the six types of structure diagrams:

  • Class diagrams: These diagrams are the foundational principle of any object-oriented software system. You can have a set of classes and a few sets of relationships between them to depict the structure and guide your software development.

  • Component diagrams: These diagrams show the organizational structure of physical elements in a software system. They help engineers and developers understand whether the systems need additional improvements or if their original structure performs efficiently.

  • Composite structure diagrams: These diagrams show the internal structure of a class and how it communicates with other parts of the system. It also includes collaborations between different classes and their interfaces.

  • Deployment diagrams: These diagrams show software engineers and developers what hardware components are available and which type of software components can efficiently run them. They're beneficial when multiple machines with diverse configurations are distributing or utilizing the software.

  • Object diagrams: These diagrams show the relationship between the system's functions and characteristics. It also includes the objects' behaviour, which helps software developers understand how different objects work and their purpose within the system.

  • Package diagrams: Packages are the various levels that may contribute to a system's architecture and package diagrams. They help engineers and developers organize their diagrams into groups, making them easier to understand.

Behavioural diagrams

Behavioural diagrams show how a proper system functions. The following are the seven kinds of behavioural diagrams:

  • Use case diagrams: These diagrams show the parts or functionality of a system and how they relate to each other. It gives developers a clear understanding of how things function without looking into implementation details.

  • Activity diagrams: These diagrams depict a system's flow of control, and software developers use them as a reference to follow steps when executing a use case diagram. Activity diagrams can also depict the causes of a particular event.

  • Sequence diagrams: These diagrams show how objects communicate with each other sequentially. Software developers commonly use them to document and understand the requirements to establish new systems or learn about existing systems.

  • Communication diagrams: These diagrams show the sequential exchange of messages between objects. They're like sequence diagrams, but communication diagrams offer more flexibility.

  • Interaction overview diagrams: These diagrams use different interaction programs to show the sequence of actions. They help developers change complex interactions into simple events.

  • State machine diagrams: These diagrams describe how objects behave in different ways in their present state. They also show how the system changes when an object's state changes.

  • Time diagrams: These diagrams are a type of sequence diagram that show the objects' behaviour. Developers use them to illustrate duration constraints and the required time to control changes in the objects' behaviour.

Tips for creating UML diagrams

Now that you understand the different UML diagrams and how to use them, here are some tips to help you get started:

Keep it simple

When creating these diagrams, remember to keep them as simple as possible. The goal is to communicate the design or structure of the system, not to show every single detail. When diagrams are complex, they can be challenging to understand.

Use the correct notation

These diagrams include many notations. When creating a diagram, be sure to use the most appropriate notation for the specified task. You can also use multiple notations in the same diagram to make it more understandable.

Label everything

When labelling objects in a diagram, include all relevant information. By providing enough information, you can make it easier for others to understand the diagram. Plus, it helps you keep track of the diagram's different objects.

Create a legend

If you're using multiple symbols or notations in your diagram, create a legend. This helps others understand the meaning of each symbol. It also makes it easier to reference the diagram when you're working on it.

Make it easy to read

Use clear and concise labels, and arrange the objects in the diagram so they're easy to understand. The goal is to make the diagram as easy to read as possible. Others are more likely to use and reference an easy-to-read diagram.

Check for errors

Before sharing your diagram with others, check it for errors. A mistake in a diagram can be costly, so it's important to make sure the diagram is accurate. You can use various tools to check for errors in your diagram.

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