Design a Restaurant Management System
What is the Restaurant Management Problem?
Section titled “What is the Restaurant Management Problem?”Design a Restaurant Management System that handles table reservations, order placement, billing, and menu management. The system should manage table availability, detect reservation conflicts, track order status, and generate bills with tax and tip calculations. The system should support concurrent reservation requests while maintaining data consistency.
In this problem, you’ll design a system that manages the entire customer journey—from booking a table to paying the bill—while coordinating between the dining area, the kitchen, and the billing desk.
Problem Overview
Section titled “Problem Overview”Design a system to streamline restaurant operations, focusing on efficient table turnover, order accuracy, and transparent billing.
Core Requirements
Section titled “Core Requirements”Functional Requirements:
- Table Management: Track states (Available, Reserved, Occupied, Cleaning) and capacities.
- Reservations: Book by date, time, and party size; automatically assign smallest suitable table.
- Conflict Prevention: Detect and prevent overlapping reservations for the same table.
- Menu Management: Organize items by category with detailed pricing.
- Order Flow: Place orders associated with tables; track status (Placed → Preparing → Served → Completed).
- Billing: Generate bills including item prices, tax, and optional tip percentages.
- Pricing Strategies: Support different models (Happy Hour, Seasonal) and discounts (Percentage, Fixed).
- Order Types: Handle different fulfillment modes (Dine-in, Takeout) using Factory Pattern.
- Concurrency: Manage simultaneous reservation requests safely to avoid double-booking.
Non-Functional Requirements:
- Separation of Concerns: Clear OOD roles for Restaurant, Table, Reservation, Order, and Bill.
- Extensibility: Easy to add new table states, order statuses, or payment methods.
- Efficiency: Optimized algorithms for conflict detection and table assignment.
- Thread Safety: Ensure data consistency during concurrent updates to reservations or orders.
What’s Expected?
Section titled “What’s Expected?”1. System Architecture
Section titled “1. System Architecture”The system coordinates between the ReservationService, OrderManager, and BillingService.
2. Key Classes to Design
Section titled “2. Key Classes to Design”classDiagram
class Table {
-int id
-int capacity
-TableState state
+reserve()
+occupy()
}
class Order {
-String id
-Table table
-List~OrderItem~ items
-OrderStatus status
+addItem(item)
+calculateSubtotal()
}
class MenuItem {
-String name
-double price
-Category category
}
class Reservation {
-Customer customer
-Table table
-DateTime startTime
-int partySize
}
Table "1" -- "0..1" Reservation
Table "1" -- "many" Order
Order "1" *-- "many" OrderItem
OrderItem --> MenuItem
System Flow
Section titled “System Flow”Order to Bill Flow
Section titled “Order to Bill Flow”
Key Design Challenges
Section titled “Key Design Challenges”1. Smart Table Assignment
Section titled “1. Smart Table Assignment”If a party of 2 arrives, you shouldn’t put them at a table for 8 if a table for 2 is available.
Solution: Implement a Table Assignment Strategy. The system searches for the smallest available table that fits the party size (table.capacity >= partySize) and matches the requested time slot.
2. Reservation Conflicts
Section titled “2. Reservation Conflicts”Checking if a table is free for a 2-hour window requires checking all other reservations for that specific table.
Solution: Use Interval Overlap Detection. A new reservation [startA, endA] conflicts with an existing one [startB, endB] if startA < endB AND startB < endA. This check must be performed within a database transaction or a synchronized block.
3. Dynamic Bill Modifiers
Section titled “3. Dynamic Bill Modifiers”A bill might have a 10% Happy Hour discount, a 5% service charge, and a 8% tax.
Solution: Use the Decorator Pattern or Strategy Pattern. The BillCalculator can apply a chain of modifiers (Tax, Discount, ServiceCharge) to the subtotal. This makes it easy to add or remove specific charges without changing the core billing logic.
What You’ll Learn
Section titled “What You’ll Learn”By solving this problem, you’ll master:
- ✅ Resource Scheduling - Managing time-based allocation of physical assets.
- ✅ State Transitions - Coordinating complex lifecycles for tables and orders.
- ✅ Financial Logic - Building robust and extensible billing engines.
- ✅ Concurrency Control - Handling high-volume booking and updates safely.
View Complete Solution & Practice
Section titled “View Complete Solution & Practice”Ready to see the full implementation? Open the interactive playground to access:
- 🎯 Step-by-step guidance through the 8-step LLD approach
- 📊 Interactive UML builder to visualize your design
- 💻 Complete Code Solutions in Python, Java, C++, TypeScript, JavaScript, C#
- 🤖 AI-powered review of your design and code
Related Problems
Section titled “Related Problems”After mastering Restaurant Management, try these similar problems:
- Hotel Management - More complex reservation and room states.
- Library Management - Resource tracking and borrowing rules.
- Movie Ticket Booking - High-concurrency seat allocation.