Class Diagram for Hospital Management System: Full UML Example

Hospital management systems are one of the most commonly requested class diagram examples — they appear in textbooks, university assignments, and system design discussions because they have a rich set of real-world relationships to model.

This post provides a complete, realistic UML class diagram for a hospital management system, broken into subsystems. All examples use Mermaid syntax so you can paste them directly into the free Badger tool and export PNG or SVG.

Core Entities: Patient, Doctor, and Appointment

classDiagram
  class Person {
    <<abstract>>
    +String personId
    +String firstName
    +String lastName
    +Date dateOfBirth
    +String phone
    +String email
    +getFullName() String
    +getAge() int
  }
  class Patient {
    +String patientId
    +String bloodType
    +MedicalHistory history
    +registerPatient() void
    +getActiveAdmissions() List
  }
  class Doctor {
    +String doctorId
    +String specialization
    +String licenseNumber
    +List schedule
    +getAvailableSlots() List
    +prescribe(medicine) Prescription
  }
  class Appointment {
    +String appointmentId
    +DateTime scheduledTime
    +String status
    +String notes
    +confirm() void
    +cancel() void
    +reschedule(newTime) void
  }
  Person <|-- Patient
  Person <|-- Doctor
  Patient "1" --> "0..*" Appointment : books
  Doctor "1" --> "0..*" Appointment : attends

Ward and Bed Management

classDiagram
  class Ward {
    +String wardId
    +String wardName
    +String wardType
    +int totalBeds
    +getAvailableBeds() int
    +getOccupancyRate() float
  }
  class Bed {
    +String bedId
    +String bedType
    +bool isOccupied
    +assignPatient(patient) void
    +discharge() void
  }
  class Admission {
    +String admissionId
    +Date admittedOn
    +Date dischargedOn
    +String diagnosis
    +String status
    +discharge() void
  }
  Ward *-- Bed
  Bed "1" --> "0..1" Admission : hosts
  Patient "1" --> "0..*" Admission : has

Ward owns Beds (composition — no Bed exists without a Ward). An Admission links a specific Patient to a specific Bed during their hospital stay.

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Prescription and Medication

classDiagram
  class Prescription {
    +String prescriptionId
    +Date issuedDate
    +Date expiryDate
    +String instructions
    +isValid() bool
    +getPrescribedItems() List
  }
  class PrescriptionItem {
    +String medicineId
    +int dosage
    +String frequency
    +int durationDays
  }
  class Medicine {
    +String medicineId
    +String name
    +String genericName
    +float stockLevel
    +reorder() void
  }
  Doctor "1" --> "0..*" Prescription : issues
  Prescription *-- PrescriptionItem
  PrescriptionItem --> Medicine

Prescriptions own their items (composition). Each item references a Medicine from the inventory — an association, not composition, since Medicine exists independently of any prescription.

Billing and Insurance

classDiagram
  class Bill {
    +String billId
    +Date generatedDate
    +float totalAmount
    +float paidAmount
    +String status
    +generateBill() void
    +processPayment(amount) void
    +getBalance() float
  }
  class BillItem {
    +String description
    +float amount
    +String itemType
  }
  class Insurance {
    +String insuranceId
    +String provider
    +String policyNumber
    +float coverageLimit
    +float coveragePercent
    +validateCoverage(amount) bool
  }
  Admission --> Bill : generates
  Bill *-- BillItem
  Patient "0..1" --> "1" Insurance : covered by

Staff and Department Structure

classDiagram
  class Department {
    +String departmentId
    +String name
    +String location
    +getStaffCount() int
  }
  class Staff {
    +String staffId
    +String role
    +String shift
    +Date hireDate
    +clockIn() void
    +clockOut() void
  }
  class Nurse {
    +String nurseId
    +String certifications
    +assignToWard(ward) void
  }
  Department *-- Staff
  Staff <|-- Doctor
  Staff <|-- Nurse
  Department "1" --> "1..*" Ward : manages

This shows that Doctors and Nurses are both Staff (inheritance), Staff belong to Departments (composition), and Departments manage Wards (association with cardinality).

Frequently Asked Questions

Is this class diagram suitable for a university assignment on hospital management?

Yes, with adjustments to match your course requirements. The structure covers the main entities and relationships typically expected. You can add or remove classes and attributes based on your specific system scope.

Why is Ward to Bed shown as composition but Patient to Admission as association?

Beds are owned by Wards — if a Ward is deleted, the beds cease to exist. But an Admission record can be kept after a Ward or Bed changes. The Patient-to-Admission relationship is a directed association because the Admission has its own lifecycle beyond the Patient.

How do I draw this diagram in the free online tool?

Copy any of the Mermaid code blocks above and paste them into the Badger Class Diagram tool. The diagram renders live. Click Export PNG to download or Export SVG for a vector file.

Can I combine all the subsystems into one diagram?

You can, but readability suffers above about 15 classes. Consider keeping the subsystems separate and cross-referencing with notes, or showing only the core entities (Patient, Doctor, Appointment, Admission) in a single overview diagram.