Class Diagram Examples: 30+ Free UML Class Diagrams for BSIT Capstones (2026)

itsourcecode.com hosts 30+ free Class Diagram examples for BSIT capstone projects (2026): complete UML class diagrams showing classes, attributes, methods, and relationships (association, aggregation, composition, inheritance) for the most common capstone domains. Capstone-ready for Chapter 3 documentation.
What is a Class Diagram?
A Class Diagram is a UML structural diagram that models the static structure of an object-oriented system. Each class is shown as a three-section rectangle: Class Name (top), Attributes (middle, properties with their data types), Methods (bottom, operations the class performs). Classes connect with relationships: Association (solid line, uses), Aggregation (open diamond, has-a), Composition (filled diamond, owns), Inheritance (open triangle, is-a). Class diagrams are mandatory for OOP-based capstones (Java, C#, Python) and strongly recommended for any modern system.
Class Diagram vs ER Diagram: what is the difference?
Class Diagram is for object-oriented design, classes have BOTH data (attributes) AND behavior (methods). Use for system architecture. ER Diagram is for database design, entities have ONLY data (attributes). Use for database schema. A capstone typically needs BOTH: the ERD models your database, the class diagram models your code. The two often share similar names (Student, Book, Order) but represent different concerns.
Featured Class diagrams by system domain
🎓 School, Student & Library

Student Management Class
Student Course Registration Class
School Management Class
College Management Class
University Management Class
Library Management Class
Hostel Management Class
Online Examination Class

🏥 Hospital & Blood Bank

Hospital Management Class
Online Blood Bank Class

🍽️ Hotel, Restaurant & Hospitality

Hotel Management Class
Restaurant Management Class
Online Food Ordering Class
Event Management Class

🛒 E-commerce, Shop & Inventory

E-commerce Website Class
Online Shopping System Class
Online Shopping Cart Class
Order Processing System Class
Point of Sales Class
Inventory Management Class

🏦 ATM, Banking & Payroll

ATM System Class
Online Banking Class
Bank Management Class
Credit Card Processing Class
Employee Payroll Class
Payroll Management Class

🚗 Transport, Travel & Reservation

Airline Reservation Class
Online Railway Reservation Class
Online Car Rental Class

🔐 Authentication & AI

Login and Registration Class
Login System Class
Face Recognition Attendance Class

About this Class diagram collection
Curated since 2015 by PIES Information Technology Solutions, Binalbagan, Negros Occidental, Philippines. Used by 12,000+ BSIT students monthly. Pair each Class diagram with the matching Sequence Diagram and Use Case for full object-oriented Chapter 3 documentation.
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Sequence Diagrams, 35+ Sequence diagrams (object interaction)
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