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.

Related UML diagram collections

• UML Diagrams Library — parent collection, 300+ diagrams
• ER Diagrams — 35+ ERDs (database design counterpart)
• Data Flow Diagrams — 40+ DFDs
• Use Case Diagrams — 40+ Use Cases
• Sequence Diagrams — 35+ Sequence diagrams (object interaction)
• Activity Diagrams — 30+ Activity diagrams
• Components Diagrams
• Deployment Diagrams
• Final Year Projects