4 - NextGenHealth: Modeling the Appointment Scheduling Domain — Where Real-World Workflows Meet Clean Architecture

Turning Scheduling Chaos into Order

In healthcare, a missed appointment isn’t just a gap in the calendar — it’s a patient’s delayed care.
Yet, most systems still treat scheduling as an afterthought: double-bookings, overlapping appointments, silent cancellations.

At NextGenHealth, I’m building something different.

After finalizing the Patient Management and Authentication domain models, I turned to Appointment Scheduling — one of the most critical, and most broken, workflows in healthcare systems.

This isn’t just “booking a time.”
It’s a real-time, rule-enforced, auditable process that must balance:

• Patient self-service

• Staff efficiency

• Doctor availability

• Compliance

So I built a domain model that reflects this complexity — not with code, but with clear, intentional relationships.

The Core of Model

The Appointment Scheduling domain model is built around six key entities:

✅ 1. Appointment

The central record of a scheduled event, including:

• Patient and doctor

• Date, time, duration

• Type (consultation, follow-up, examination)

• Status (scheduled, confirmed, completed, cancelled)

✅ 2. Patient & Doctor

Actors in the scheduling process:

• Patient books, views, and manages appointments

• Doctor has availability and receives notifications

✅ 3. AvailabilitySlot

A time slot that can be booked — the key to preventing double-booking.

This is not just a boolean flag. It’s a first-class entity that:

• Is checked in real-time

• Becomes an Appointment when booked

• Ensures REQ-APP-002 (no doctor double-booking) and REQ-APP-003 (no patient overlap)

✅ 4. Notification

Triggers automated messages:

• Confirmation (email/SMS)

• Reminders (48h, 24h)

• Doctor alerts (within 1 hour)

Aligned with REQ-APP-010, REQ-APP-011, REQ-APP-012

✅ 5. AuditLogTrail

Not a generic log — but a trail of scheduling actions:

• Who booked the appointment

• When it was created

• Which patient and doctor were involved

Supports REQ-SEC-003 — full auditability

✅ 6. Nurse & Administrator

Staff who can book on behalf of patients, a common workflow in clinics.

Appointment Scheduling Domain Model

Stay in the Loop

Want to follow the journey?

🔗 Connect on LinkedIn — I post daily updates on the development process, UML decisions, and architecture insights.

📧 Need expert help on your healthcare project?

Let’s talk: contact@fmbyteshiftsoftware.com

GitHub NextGenHealth Project
Code. Design. Document. Refine.

About the Author: Fernando Antunes de Magalhães is a Software Architect with over 15 years of experience, including 11 years in healthcare technology. He holds a Post-Graduate degree in Software Engineering and is the author of “Software Engineering — Essential Principles for Beginners and Professionals” (link). He leads FM ByteShift Software, building next-generation systems with precision, compliance, and real-world impact.