Inventory API

Welcome to the Inventory API! This is a RESTful API built with Spring Boot that helps businesses manage their inventory efficiently. The application not only provides basic CRUD operations for inventory items but also implements a dynamic ordering algorithm to optimize inventory decisions over time.

Table of Contents

• Features
• Purpose
• [Dynamic Ordering Algorithm]
• Technologies
• Getting Started
• API Endpoints
• Database
• Running the Application
• License

Features

• RESTful API for inventory management
• Dynamic Ordering Algorithm to optimize inventory decisions
• In-memory H2 database for testing
• Actuator endpoints for monitoring and management
• H2 Console for easy database access during development.

Purpose

The Inventory API is developed to support businesses in making informed and dynamic decisions regarding their inventory management. It allows users to:

• Monitor Inventory Levels: Keep track of stock levels in real-time to avoid shortages or overstock situations.
• Optimize Ordering Decisions: Use the Dynamic Ordering Algorithm to determine the optimal order quantities over time, minimizing costs.
• Analyze Trends: Use historical data to identify trends and adjust inventory accordingly, ensuring optimal stock levels.
• Facilitate Quick Decisions: Provide instant access to inventory data, enabling quick responses to changes in demand or supply chain disruptions.

Dynamic Ordering Algorithm

The Dynamic Ordering Algorithm is a key feature of this application. It uses dynamic programming to solve the inventory ordering problem by breaking it into smaller sub-problems and solving them in reverse order (backward recursion). Here's how it works:

Problem Statement

You run a production facility with known demands for materials in each time period. At the beginning of each period, you can order a certain amount of material. The goal is to minimize the total cost, which includes: Ordering Cost: A fixed cost for placing an order. Holding Cost: The cost of holding inventory from one period to the next.

How It Works

Stages and States: Each time period represents a stage. The state at each stage is the inventory level at the end of the period. Backward Recursion: Start from the last period and work backward to the first. At each stage, calculate the optimal cost for each possible inventory level. Cost Function: The cost function includes: Ordering Cost: Fixed cost if an order is placed. Holding Cost: Cost of holding inventory to the next period. Optimal Policy: The algorithm determines the optimal order quantities for each period to minimize total costs. Example

For a demand sequence [10, 20, 30, 40], the algorithm calculates the optimal order quantities and associated costs for each period.

Technologies

• Java 21
• Spring Boot
• H2 Database
• Gradle

Getting Started

Prerequisites

• Java Development Kit (JDK) 17 or later
• Gradle

Installation

1. Clone the repository:

   git clone https://github.com/1927-med/inventory.git
   cd inventory
   

Build the application:

./gradlew build

Run the application:

./gradlew bootRun

API Endpoints

Inventory Management

GET /api/items: Get all inventory items. POST /api/items: Add a new inventory item. GET /api/items/{id}: Get an item by ID. PUT /api/items/{id}: Update an item by ID. DELETE /api/items/{id}: Delete an item by ID.

Dynamic Ordering Algorithm

POST /api/ordering/solve: Solve the dynamic ordering problem. Parameters: orderingCost: Fixed cost for placing an order. holdingCost: Cost of holding one unit of inventory. demands: Array of demands for each time period (e.g., [10, 20, 30, 40]).

Actuator Endpoints

GET /actuator: Access actuator endpoints for monitoring and management.

H2 Console Access H2 Console: http://localhost:8080/h2-console JDBC URL: jdbc:h2:mem:inventorydb Username: sa Password: (leave it empty)

Database

This API uses an in-memory H2 database. You can access the H2 console at http://localhost:8080/h2-console to view and interact with the database.

Running the Application

To run the application, use the following command:

./gradlew bootRun

Instructions to Create the README File

1. Create a file named README.md in the root directory of your project.
2. Copy and paste the above content into the README.md file.
3. Customize any sections as necessary, especially the "Getting Started" and "API Endpoints" sections, to include any additional endpoints or specific instructions for your application.

Creater Note

I am a university student and would like any advice for improvement and i will continue to upgrade the project