Smart Inventory POS & Invoice System

A comprehensive Point of Sale and Inventory Management System with barcode tracking, audit logging, and automated reporting.

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Table of Contents

• About the Project
• Project Overview
• Key Features
• Tech Stack
• Dependencies
• Installation & Setup
• Folder Structure
• Database Relation Analysis
• System Design Analysis
• Traceability Matrix
• Visual Showcase
• Contributions
• License
• Contact

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About the Project

The Smart Inventory POS & Invoice System is a professional-grade solution designed to streamline retail operations. It integrates product cataloging, real-time inventory tracking, and automated sales processing into a single, cohesive platform. By leveraging barcode scanning and automated reporting, it helps businesses eliminate manual errors and gain real-time insights into their performance.

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Project Overview

This project is built using the Laravel Repository + Service Layer architectural pattern to ensure high maintainability and scalability. It provides a robust backend for handling complex financial transactions and stock movements, while the frontend offers a responsive interface for both administrators and cashiers.

Key Metrics & Objectives:

• Accuracy: Real-time stock updates and automated VAT/discount calculations.
• Accountability: Full audit trail for every product change and sale transaction.
• Efficiency: Fast POS checkout workflow with keyboard-wedge barcode scanner support.

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Key Features

• User Authentication: Secure login with role-based access control (Admin, Cashier).
• Inventory Management: Full CRUD for products, categories, subcategories, and suppliers with barcode tracking.
• POS Workflow: Seamless sales process with cart management, invoice generation, and multiple payment methods (Cash, Card, Mobile).
• Customer Ledger: Financial tracking system for managing customer debts, credits, and balance history.
• Stock-In/Out Tracking: Managed through purchase orders and stock adjustments with status tracking.
• Automated Reporting: Daily/Weekly sales reports, top-product analysis, and low-stock alerts via reorder thresholds.
• Export/Import Tools: Bulk product data handling via Excel and barcode label generation to PDF.

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Tech Stack

Backend: Laravel 12 · PHP 8.2+
Frontend: React.js · Tailwind CSS 4 · Vite
Database: MySQL · PostgreSQL · SQLite
Tools: Git · VS Code · Composer · PNPM · Docker (Sail)

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Dependencies

List of major libraries and frameworks used:

{
  "php": "^8.2",
  "laravel/framework": "^12.0",
  "barryvdh/laravel-dompdf": "*",
  "maatwebsite/excel": "*",
  "picqer/php-barcode-generator": "*",
  "tailwindcss": "^4.0.0",
  "vite": "^7.0.7"
}

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Installation & Setup

1. Clone the repository:

   git clone <repo-url> pos-management
   cd pos-management

2. Install PHP dependencies:

   composer install

3. Install frontend dependencies:

   pnpm install

4. Environment Configuration:

   cp .env.example .env
   php artisan key:generate

   Configure your database credentials in the .env file.
5. Database Setup:

   php artisan migrate --seed

6. Build Frontend Assets:

   pnpm run build

7. Start the Server:

   php artisan serve

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Folder Structure

app/
├── Http/
│   ├── Controllers/    # Thin controllers
│   ├── Requests/       # Form validations
├── Models/             # Eloquent entities
├── Repositories/       # Data abstraction layer
├── Services/           # Business logic (SaleService, StockService, etc.)
database/
├── migrations/         # Database schema
├── seeders/            # Initial roles and data
resources/
├── js/                 # React components and logic
├── views/              # Blade templates

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Database Relation Analysis

Core Entities & Relationships

Entity	Description	Relationships
User	System users (Admin, Cashier)	HasMany Sales, HasMany AuditLogs
Category	Product classifications	HasMany Products
Supplier	Product providers	HasMany Products, HasMany Purchases
Product	Inventory items	BelongsTo Category, BelongsTo Supplier, HasMany SaleItems, HasMany StockAdjustments
Purchase	Stock-in transactions	BelongsTo Supplier, HasMany PurchaseItems
PurchaseItem	Individual items in a purchase	BelongsTo Purchase, BelongsTo Product
Customer	Clients/Buyers	HasMany Sales, HasMany CustomerLedger
Sale	POS transactions (Stock-out)	BelongsTo Customer (nullable), BelongsTo User, HasMany SaleItems
SaleItem	Individual products in a sale	BelongsTo Sale, BelongsTo Product
CustomerLedger	Financial tracking (Due/Debit/Credit)	BelongsTo Customer
StockAdjustment	Manual stock corrections	BelongsTo Product, BelongsTo User
AuditLog	System activity tracking	BelongsTo User

ER Diagram (Mermaid)

erDiagram
    USERS ||--o{ SALES : "processes"
    USERS ||--o{ AUDIT_LOGS : "performs"
    CATEGORIES ||--o{ PRODUCTS : "contains"
    SUPPLIERS ||--o{ PRODUCTS : "supplies"
    SUPPLIERS ||--o{ PURCHASES : "provides"
    PURCHASES ||--o{ PURCHASE_ITEMS : "includes"
    PRODUCTS ||--o{ PURCHASE_ITEMS : "bought_in"
    CUSTOMERS ||--o{ SALES : "makes"
    CUSTOMERS ||--o{ CUSTOMER_LEDGER : "has_history"
    SALES ||--o{ SALE_ITEMS : "contains"
    PRODUCTS ||--o{ SALE_ITEMS : "sold_in"
    PRODUCTS ||--o{ STOCK_ADJUSTMENTS : "adjusted"
    USERS ||--o{ STOCK_ADJUSTMENTS : "authorized"

    USERS {
        bigint id PK
        string name
        string username "unique"
        string password
        enum role "Admin, Cashier"
    }
    PRODUCTS {
        bigint id PK
        string name
        string barcode "unique"
        decimal cost_price
        decimal selling_price
        integer stock_quantity
        integer reorder_level
    }
    SALES {
        bigint id PK
        string invoice_number "unique"
        decimal total_amount
        decimal discount_amount
        decimal vat_amount
        decimal net_amount
        enum payment_method "Cash, Card, Mobile"
    }

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System Design Analysis

Architectural Pattern: Repository + Service Layer

1. Models (Eloquent): Represent the database tables and define relationships.
2. Repositories: Abstraction layer for data fetching (e.g., finding products by barcode).
3. Service Layer: Handles "Business Logic" (e.g., SaleService manages transactions, updates stock, and customer ledger in a single DB transaction).
4. Audit Observers: Automatically record AuditLog entries whenever sensitive data (Product/Sale) is modified.

Key Module Interactions

• POS Module: Cashier scans barcode -> Frontend fetches details -> Sale finalized -> SaleService updates stock -> CustomerLedger updated -> InvoiceService generates PDF.
• Inventory Module: Stock falls below reorder_level -> System triggers "Low Stock" alert for reporting.

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Traceability Matrix

Feature	Implementation Detail
Login + Roles	USERS table with role enums; Middleware for access control.
Products (CRUD)	PRODUCTS, CATEGORIES, SUPPLIERS tables + ProductController.
Stock In/Out	PURCHASES (In), SALE_ITEMS (Out), STOCK_ADJUSTMENTS.
POS Interface	Fast search via barcode; SALES and SALE_ITEMS tracking.
VAT & Discounts	Financial fields in SALES table for precise net calculation.
Invoice PDF	InvoiceService using Laravel DOMPDF.
Customer Ledger	CUSTOMERS table + CUSTOMER_LEDGER debit/credit history.
Audit Log	AUDIT_LOGS table with user-to-action mapping.

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Visual Showcase

🏠 Home & Landing

🔐 Authentication

🛠️ Admin Management

🛒 Cashier & POS Terminal

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Contributions

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

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License

Distributed under the MIT License. See LICENSE for more information.

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Contact

Project Maintainer: Md Rafiul Islam
Project Link: https://github.com/Rafiul29/point-of-sale.git