# How Amazon Optimizes Where to Store Products to Avoid Stockouts

> A mathematical method for deciding how many items to stock in different warehouses to minimize the cost of running out of products.

- **Patent:** US 8732039
- **Original title:** Allocating regional inventory to reduce out-of-stock costs
- **Owner:** Amazon Technologies Inc
- **Granted:** 2014
- **Status:** Active
- **Times cited:** 41
- **Field:** ecommerce, ai_ml

## What it does

This patent describes a computational method for distributing a fixed supply of goods across multiple regional warehouses. It uses a probabilistic model—specifically a gamma distribution—to forecast customer demand in each region. By calculating the specific financial cost of an out-of-stock event in each location, the system determines the optimal number of units to store in each warehouse. The goal is to minimize the total expected cost across the entire network, ensuring that high-demand or high-cost-of-failure regions receive priority in inventory allocation.

## What it does NOT cover

- Does not cover real-time inventory replenishment triggered by individual customer purchases.
- Does not cover the physical logistics of transporting goods between warehouses.
- Does not cover demand forecasting methods that do not utilize a probabilistic distribution model.
- Does not cover manual inventory management decisions made without the specified mathematical optimization.

## The clever bit

The system treats the 'cost of being out of stock' as a variable that can be balanced across regions using a set of equations, effectively equalizing the marginal risk of stockouts across the entire network.

## Real-world examples

1. Amazon fulfillment center inventory distribution
2. Automated supply chain management software
3. Regional warehouse stock level planning

## Why it matters

This technology is fundamental to modern e-commerce, where the speed of delivery is a primary competitive advantage. By mathematically balancing inventory across a vast network, companies like Amazon can reduce shipping costs and avoid the significant financial penalty of failing to fulfill an order from the nearest warehouse. It transformed inventory management from a reactive process into a predictive, data-driven optimization problem.

## Frequently asked questions

### What does How Amazon Optimizes Where to Store Products to Avoid Stockouts cover?

A mathematical method for deciding how many items to stock in different warehouses to minimize the cost of running out of products.

### Who owns patent US 8732039?

Amazon Technologies Inc owns this patent, granted in 2014.

### When does this patent expire?

This patent is expected to expire on May 20, 2034, when the invention enters the public domain.

### What is patent US 8732039 cited by?

This patent has been cited by 41 later patents that build on its ideas.

### What problem does this patent solve?

This technology is fundamental to modern e-commerce, where the speed of delivery is a primary competitive advantage. By mathematically balancing inventory across a vast network, companies like Amazon can reduce shipping costs and avoid the significant financial penalty of failing to fulfill an order from the nearest warehouse. It transformed inventory management from a reactive process into a predictive, data-driven optimization problem.

### What does this patent NOT cover?

Does not cover real-time inventory replenishment triggered by individual customer purchases.

**Full plain-English explainer:** https://patentbrief.org/patent/us/8732039/amazon-subscribe-save

**Original patent:** https://patents.google.com/patent/US8732039

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._