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Design a Restaurant Management System - Low-Level Design | OneNoughtOne

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Design a Restaurant Management System

Intermediate

Design an object-oriented restaurant management system that handles menu management (items with categories and availability), table tracking (available / occupied / reserved), reservations and walk-in seating, order placement with per-item status (pending → preparing → ready → served), kitchen queue processing, and billing with tax, service charge, discounts, tip, and bill splitting.

Tables are auto-created with varying capacities. Orders belong to a table and flow through a kitchen queue. Bills are generated from completed orders and include configurable tax (10%) and service charge (5%). Staff (waiters, chefs, hosts) can be assigned to tables.

Core Use Cases

Menu management

Add/remove/update menu items with categories, prices, and availability

Table management

Track table status (available, occupied, reserved, out-of-service)

Make reservation

Reserve a table for a party size and time; assign an appropriate table

Seat walk-in

Assign the first available table for a walk-in party

Place order

Add menu items (with quantity and special instructions) to a table's order

Kitchen processing

Send order to kitchen queue; track item prep status (pending → preparing → ready)

Generate bill

Calculate subtotal, tax, service charge, discounts, and tip

Pay bill and release table

Accept payment (cash/card/UPI), mark bill paid, release table

Staff assignment

Assign waiters to tables; track clock-in/out

Constraints

A table can only hold one active order at a time
Reservation must match party size to table capacity (party ≤ capacity)
Order items can only be removed while in PENDING status
Bill = subtotal + tax (10%) + service charge (5%) − discount + tip
A table must be released (made available) after the bill is paid

Assumptions

In-memory storage (no database)
Single restaurant branch
Single-threaded (concurrency is a follow-up)
No online ordering or delivery (dine-in only)
Simplified payment — no gateway integration

In Scope

Menu with categories and availability
Table lifecycle management
Reservation and walk-in seating
Order with per-item status tracking
Kitchen queue for preparation tracking
Bill with tax, service charge, discount, tip, and split
Staff roles and table assignment

Out of Scope

Online ordering and delivery
Inventory / ingredient tracking
Customer loyalty programs
Multi-branch management
Real-time kitchen display system

Approach Guide(Click to expand each section)

Before diving into code, clarify the use cases and edge cases. Understanding the problem deeply leads to better class design.

List Core Use Cases

Identify the primary actions users will perform. For a parking lot: park vehicle, exit vehicle, check availability. Each becomes a method.

Identify Actors

Who interacts with the system? Customers, admins, automated systems? Each actor type may need different interfaces.

Clarify Constraints

What are the limits? Max vehicles, supported vehicle types, payment methods. Constraints drive your data structures.

Ask About Edge Cases

What happens on overflow? Concurrent access? Payment failures? Thinking about edge cases reveals hidden complexity.

Follow-up Questions(Questions an interviewer might ask)

💡 Draw UML class diagrams, sequence diagrams, or any design visualizations. Submit from the Code tab.

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00:00:00

Design a Restaurant Management System

Intermediate

Core Use Cases

Menu management

Add/remove/update menu items with categories, prices, and availability

Table management

Track table status (available, occupied, reserved, out-of-service)

Make reservation

Reserve a table for a party size and time; assign an appropriate table

Seat walk-in

Assign the first available table for a walk-in party

Place order

Add menu items (with quantity and special instructions) to a table's order

Kitchen processing

Send order to kitchen queue; track item prep status (pending → preparing → ready)

Generate bill

Calculate subtotal, tax, service charge, discounts, and tip

Pay bill and release table

Accept payment (cash/card/UPI), mark bill paid, release table

Staff assignment

Assign waiters to tables; track clock-in/out

Constraints

A table can only hold one active order at a time
Reservation must match party size to table capacity (party ≤ capacity)
Order items can only be removed while in PENDING status
Bill = subtotal + tax (10%) + service charge (5%) − discount + tip
A table must be released (made available) after the bill is paid

Assumptions

In-memory storage (no database)
Single restaurant branch
Single-threaded (concurrency is a follow-up)
No online ordering or delivery (dine-in only)
Simplified payment — no gateway integration

In Scope

Menu with categories and availability
Table lifecycle management
Reservation and walk-in seating
Order with per-item status tracking
Kitchen queue for preparation tracking
Bill with tax, service charge, discount, tip, and split
Staff roles and table assignment

Out of Scope

Online ordering and delivery
Inventory / ingredient tracking
Customer loyalty programs
Multi-branch management
Real-time kitchen display system

Approach Guide(Click to expand each section)

Before diving into code, clarify the use cases and edge cases. Understanding the problem deeply leads to better class design.

List Core Use Cases

Identify the primary actions users will perform. For a parking lot: park vehicle, exit vehicle, check availability. Each becomes a method.

Identify Actors

Who interacts with the system? Customers, admins, automated systems? Each actor type may need different interfaces.

Clarify Constraints

What are the limits? Max vehicles, supported vehicle types, payment methods. Constraints drive your data structures.

Ask About Edge Cases

What happens on overflow? Concurrent access? Payment failures? Thinking about edge cases reveals hidden complexity.

Follow-up Questions(Questions an interviewer might ask)

💡 Draw UML class diagrams, sequence diagrams, or any design visualizations. Submit from the Code tab.

Loading canvas...

Design a Restaurant Management System

Core Use Cases

Constraints

Assumptions

In Scope

Out of Scope

Approach Guide(Click to expand each section)

Follow-up Questions(Questions an interviewer might ask)

Explore the full editorial.

Sign in to view submissions

Design a Restaurant Management System

Core Use Cases

Constraints

Assumptions

In Scope

Out of Scope

Approach Guide(Click to expand each section)

Follow-up Questions(Questions an interviewer might ask)

Explore the full editorial.

Sign in to view submissions

Design a Restaurant Management System

Core Use Cases

Constraints

Assumptions

In Scope

Out of Scope

Approach Guide(Click to expand each section)

Gather Requirements~3 min

Identify Classes & Entities~4 min

Define Relationships~3 min

Apply Design Patterns~4 min

Apply SOLID Principles~3 min

Code Organization~2 min

Follow-up Questions(Questions an interviewer might ask)

1How would you handle concurrent reservation requests for the last available table?

2How would you add dynamic pricing (happy hour, surge pricing)?

3How would you integrate online ordering and delivery?

4How would you add ingredient-level inventory tracking?

5How would you implement a table wait-list for busy periods?

Key Topics

Asked At

Explore the full editorial.

Sign in to view submissions

Design a Restaurant Management System

Core Use Cases

Constraints

Assumptions

In Scope

Out of Scope

Approach Guide(Click to expand each section)

Gather Requirements~3 min

Identify Classes & Entities~4 min

Define Relationships~3 min

Apply Design Patterns~4 min

Apply SOLID Principles~3 min

Code Organization~2 min

Follow-up Questions(Questions an interviewer might ask)

1How would you handle concurrent reservation requests for the last available table?

2How would you add dynamic pricing (happy hour, surge pricing)?

3How would you integrate online ordering and delivery?

4How would you add ingredient-level inventory tracking?

5How would you implement a table wait-list for busy periods?

Key Topics

Asked At

Explore the full editorial.

Sign in to view submissions