lemon-project System Requirements Document

Introduction

The lemon-project is a comprehensive RetailPOS ERP software solution designed to streamline retail operations. This document outlines the system requirements for the project, ensuring that all functionalities are clearly defined and implemented.

System Overview

The lemon-project aims to provide a robust ERP solution for retail businesses, focusing on efficient management of billing, inventory, customer relations, and reporting. The system is designed to support store managers and staff, offering features like user authentication, billing, inventory management, and more, tailored to meet the needs of retail operations in India.

Functional Requirements

• As a Store Manager, I should be able to authenticate using BCrypt passwords with role-based access.
• As a Staff, I should be able to manage billing with GST auto-calculation.
• As a Store Manager, I should be able to track inventory, including products and categories.
• As a Staff, I should be able to manage customer and supplier information with GSTIN support.
• As a Store Manager, I should be able to create, receive, and track purchase orders.
• As a Staff, I should be able to generate and view various reports, including sales and stock.
• As a Store Manager, I should be able to print invoices with auto-detect printer functionality.
• As a Staff, I should be able to send invoices via WhatsApp.
• As a Store Manager, I should receive low stock alerts automatically.
• As a Staff, I should be able to use keyboard shortcuts for efficient operations.
• As a Store Manager, I should be able to toggle between dark and light themes.
• As a Staff, I should be able to view an enhanced dashboard with real-time insights.
• As a Store Manager, I should be able to manage cash registers to prevent theft.
• As a Staff, I should be able to manage license generation, validation, and expiration.
• As a Store Manager, I should be able to perform backup and restore operations.
• As a Staff, I should be able to apply discounts at item and bill levels.
• As a Store Manager, I should be able to handle returns and refunds in compliance with Indian laws.
• As a Staff, I should be able to track batches and expiry dates for products.
• As a Store Manager, I should be able to support concurrent billing for multiple users.
• As a Staff, I should be able to manage e-invoicing and e-way bills for high turnover.
• As a Store Manager, I should be able to sync with e-commerce platforms like Shopify and WooCommerce.
• As a Staff, I should be able to access the system via a mobile app on Android/iOS.
• As a Store Manager, I should be able to manage multiple store locations.
• As a Staff, I should be able to utilize AI features for predictive analytics.

User Personas

• Store Manager: Responsible for overseeing store operations, managing inventory, and ensuring compliance with legal requirements.
• Staff: Handles day-to-day operations, including billing, customer service, and inventory management.

Core User Flows

• Store Manager logs in -> Manages inventory -> Generates reports -> Oversees billing operations
• Staff logs in -> Processes customer billing -> Sends invoices via WhatsApp -> Applies discounts and manages returns

Visuals Colors and Theme

• primary: #2A9D8F (Teal)
• primary_light: #A8DADC (Light Teal)
• secondary: #E76F51 (Coral)
• accent: #F4A261 (Orange)
• highlight: #E9C46A (Gold)
• bg: #F1FAEE (Off White)
• surface: rgba(42, 157, 143, 0.8)
• text: #264653 (Dark Blue)
• text_muted: #6D6875 (Muted Gray)
• border: rgba(233, 69, 96, 0.2)

Signature Design Concept

The lemon-project will feature an interactive 3D floating island homepage using @react-three/fiber and @react-three/drei. Each section of the ERP system will be represented as a building on the island. Users can navigate between these buildings by clicking and dragging, creating an engaging and immersive experience. The island will have dynamic lighting that changes based on the time of day, providing a visually stunning and interactive interface.

Interaction Model & Motion Direction

The landing page will utilize a "parallax" interaction model, with layered depth via scroll. Decorative elements like clouds and birds will move at different speeds, creating a sense of depth and immersion. Internal pages will adopt a "static" model to ensure clarity and focus on data-heavy tasks.

Non-Functional Requirements

• The system must support high availability and scalability to handle multiple concurrent users.
• Data security and privacy must comply with Indian regulations.
• The system should be responsive and accessible on both desktop and mobile devices.

Tech Stack

• Frontend: React for Web
• Backend: Python, FastAPI
• Database: MySQL or MariaDB
• AI Models: GPT 5.4 for user-friendly responses
• AI Tools: Litellm for LLM Routing
• Local Orchestration: Docker, docker-compose
• Server Side Orchestration: Kubernetes

Assumptions and Constraints

• The system will primarily be used in India, adhering to local tax and legal requirements.
• The system must integrate seamlessly with existing e-commerce platforms.
• The mobile app will be developed for both Android and iOS platforms.

Glossary

• ERP: Enterprise Resource Planning
• POS: Point of Sale
• GST: Goods and Services Tax
• CGST/SGST: Central/State Goods and Services Tax
• E-Invoicing: Electronic Invoicing
• E-Way Bill: Electronic Way Bill

This document provides a comprehensive overview of the requirements for the lemon-project, ensuring that all functionalities and user needs are addressed.