Last month, Walmart launched Express Delivery, a service that allows customers to receive orders in two hours or less. Pilot tests began across 100 U.S. stores on April 16, and Walmart plans to expand Express Delivery to nearly 1,000 stores tomorrow and about 2,000 later this month.

Express Delivery, which offers more than 160,000 items across Walmart’s inventory, wasn’t motivated strictly by the pandemic. But Walmart says the timing “pushed forward” development as the retailer experienced a surge in delivery demand correlated with shelter-in-place orders. Its engineering teams completed a minimum viable product and deployed it to a store in Phoenix, Arizona within two weeks, after which it was brought to 100 stores. As tests in those stores began, the teams behind Express Delivery worked on a scalable successor, optimizing it in real time for larger store deployments.

Walmart spoke with VentureBeat about the AI systems underlying Express Delivery, which range from a logistics algorithm that accounts for conditions to an alerting platform that prioritizes orders for a network of over 74,000 personal shoppers. While some systems were in place prior to Express Delivery’s development, others had to be architected from scratch.

Adding to the cart

As with any Walmart order, the Express Delivery experience begins with adding items to a cart. Via Walmart’s website or its mobile app, customers choose what they’d like to order and finalize their basket before moving to the checkout phase, where they choose the day and time they’d like their order delivered.


AI Unleashed

An exclusive invite-only evening of insights and networking, designed for senior enterprise executives overseeing data stacks and strategies.


Learn More


Behind the scenes, an AI system — which includes a “resource optimization and vehicle routing” — determines whether customers are eligible for Express Delivery, depending on a range of real-time factors. As it optimizes routes and assigns delivery trips for vehicles to ensure customers receive their orders at the proper time, the system considers:

  • The time slot
  • The number of orders assigned to that time slot
  • The vehicles and vehicle types available
  • The distance of routes between stores and the delivery address
  • Likely delays as a result of heavy precipitation, like sleet, snow, or hail

Estimated time to arrival is derived from all of these variables and serves as one of the inputs for a second AI system, a capacity and slot management system that determines which time slots and delivery slots are free. It principally looks at the number of items in an order and available labor — i.e., the number of orders and associates at any particular store on a given day and time.

Both the vehicle routing and capacity management systems had to be significantly retuned for Express Delivery, according to Walmart. That’s because in the past customers would typically build a basket for orders over the course of days and then select slots for pickup or delivery. With the advent of Express Delivery, some baskets are much smaller, and the delivery windows shorter, which necessitated more delivery drivers and vehicles on standby.

These two systems’ predictions together determine whether a customer even sees an Express Delivery option. Walmart says that within milliseconds, using real-time and historical data, it can obtain predictions, which must reach a confidence threshold to present Express Delivery as an option at checkout time.

Picking and packing

Successfully placed Express Delivery orders are routed to yet another AI system that handles fulfillment. It’s in charge of organizing orders to sequence the picking and packing of items in Walmart’s stores.

When an Express Order comes into a particular store, the system alerts personal shoppers and associates via their handheld devices. Only shoppers assigned to and trained for Expressed Delivery are alerted.

Walmart says that a shopper can pull an item off the shelf and have it ready for pickup in as little as 15 minutes. Once items have been readied for pickup, a fifth and final system takes over: delivery provider integrations. It instructs drivers to report to stores for Express Delivery pickups.

For ordinary Walmart deliveries, delivery drivers pull into designated spaces with bright orange signage, and orders are then placed inside their car. But for Express Deliveries, drivers are required to take carts containing orders from shoppers, walk those carts to their vehicles, and load them.

The Express Delivery dev teams had to add new store pickup locations — “access points” — within the system expressly for this purpose. They also worked with delivery partners to develop an app that directs drivers to the right place and provides step-by-step order execution and prep instructions.

Despite the added steps involved, Walmart asserts that Express Delivery won’t affect the delivery times of standard, cheaper orders.

Deliveries during a pandemic

When asked whether Walmart’s various automation efforts would play a role in facilitating Express Delivery, a representative demurred, saying only that the number of delivery partners the company works with might increase as service expands. Self-driving vehicle startup Gatik, which this week revealed the design of its next-generation cargo van, is handling deliveries between some Walmart fulfillment centers. Walmart also has a partnership with Nuro to deliver groceries via self-driving vehicles in Houston, Texas, as well as an arrangement with Ford and Postmates to pilot driverless delivery in portions of Miami-Dade County, Florida.

In its conversation with VentureBeat, a Walmart rep was careful to position Express Delivery as merely another way the company is meeting customer demand for speedy fulfillment. The program’s launch follows Ship to Store, which arranges for the delivery of items to stores near a customer’s address. Ship to Store taps an AI multi-channel fulfillment system that weighs millions of variables to suss out the fastest one-day, two-day, or several-day delivery option. Last month, Walmart expanded it from 130 stores to 2,400 stores in a period of one week.

Express Delivery’s rollout comes as rival Amazon, which offers a competing service in Prime Now, appears to be overwhelmed with orders. Amazon continues to prioritize the shipment of household staples, medical supplies, and other “high-demand” products at the expense of other items. And in April, Amazon’s AmazonFresh grocery service and Amazon-owned Whole Foods began artificially limiting the number of online customers by imposing an invitation system that sends shopping invites to new customers on a weekly basis.

Coronavirus outbreaks at Amazon warehouses have put a strain on the retailer’s supply chain, and it remains to be seen whether Walmart will avoid the same fate. This week, Senator Elizabeth Warren (D-MA) and other Massachusetts lawmakers probed Walmart on a store in the state where 81 workers tested positive for the coronavirus and another location where an employee died. Officials ordered the former store to shut down; it has since reopened after a deep cleaning.

Walmart associates were among those who walked out of work last month to protest what they characterized as a lackluster effort to protect their health. In response, Walmart announced that it’s working in partnership with local health officials and taking “aggressive steps” to help ensure the safety of employees and customers, hiring an undisclosed third-party company to clean and disinfect high-touch surfaces, and limiting the number of shoppers in its stores to five per 1,000 square feet.

“The platform and component architecture we’ve built are the backbone and intelligence behind Express Delivery,” said Walmart SVP Fiona Tan via email. “As we continue to add new machine learning-driven capabilities like this in the future, as well as the corresponding customer experiences, we’ll be able to iterate and scale quickly by leveraging the flexible technology platforms we’ve developed.”

Express Delivery requires a $30 minimum for orders and is a $10 upcharge on top of the usual delivery fee.

VentureBeat's mission is to be a digital town square for technical decision-makers to gain knowledge about transformative enterprise technology and transact. Discover our Briefings.