{"id":52,"date":"2023-09-04T18:36:43","date_gmt":"2023-09-04T18:36:43","guid":{"rendered":"https:\/\/libraryresources.nse.org.ng\/setextbook\/chapter\/uml-class\/"},"modified":"2026-03-16T14:21:10","modified_gmt":"2026-03-16T14:21:10","slug":"uml-class","status":"publish","type":"chapter","link":"https:\/\/libraryresources.nse.org.ng\/setextbook\/chapter\/uml-class\/","title":{"raw":"Unified Modeling Language Class and Sequence Diagrams","rendered":"Unified Modeling Language Class and Sequence Diagrams"},"content":{"raw":"
\"Chapter<\/a><\/div>\n

Chapter 4\nUnified Modeling Language Class and<\/span> Sequence Diagrams<\/h2>\n
\u201cNobody, not even the creators of the UML, understand or use all of it.\u201d (Fowler, [pb_glossary id=\"672\"]2004[\/pb_glossary]<\/span>)<\/div>\nAfter a discussion of diagrams in general, this chapter covers two common Unified Modeling Language (UML) diagram types: [pb_glossary id=\"860\"]class diagrams[\/pb_glossary] and [pb_glossary id=\"861\"]sequence diagrams[\/pb_glossary].\n

4.1 How Diagrams Help<\/h1>\nDiagrams can help in at least two major ways:\n
    \n \t
  1. They can help you plan software<\/strong> you will create. Once you\u2019ve created diagrams for planning your software, you can use them to communicate to the development team what will\/should be implemented and decide (evaluate) whether your plans are any good (e.g., are clear, are logical, reflect your project\u2019s desired quality attributes, and so on).<\/li>\n \t
  2. They can help you describe software<\/strong> you\u2019ve already created. If your software is already created, diagrams are good for documentation and, as mentioned above, for evaluating how satisfactory your software is. The purpose of including diagrams in documentation is to communicate something about your software to somebody. There are many different audiences you could be trying to communicate with.<\/li>\n<\/ol>\nExample audiences for your diagrams include other developers on the project, your supervisor or manager, developers who might be interested in joining the team, developers who want to integrate with your system, curious end users, and students of software engineering. Depending on the [pb_glossary id=\"862\"]integrated development environment (IDE)[\/pb_glossary]\/tools you\u2019re using, diagrams can be automatically generated from your code, which helps make documentation maintenance easier and more likely to happen.\n

    4.2 What Diagrams Must Do Well<\/h1>\nTo be helpful, diagrams must communicate clearly<\/strong> and at an appropriate level of detail<\/strong> for your intended audience. If your intended audience does not understand your diagram\u2014or misunderstands it\u2014your diagram has failed.\n

    4.3 What Is UML?<\/h1>\nUnified Modeling Language is a family of graphical notations for describing and designing software through diagrams. It is especially applicable to object-oriented software, but some parts of UML are applicable to many types of software. Different UML notations are used for different types of UML diagrams, each of which has a specific purpose. UML was first published in 1994, became a standard of the Object Management Group (OMG) in 1997, and became an ISO standard in 2005. UML is currently on version 2.\n

    4.4 Why Use UML?<\/h1>\nThere are multiple benefits<\/strong> of creating diagrams using UML:\n