The average order in Rohlik Group's fulfillment centers carries about 30 items. Some of them sit in a robotic storage grid. Some sit on shelves in a chilled room. The bananas, the flowers, and the twelve-pack of sparkling water live wherever bananas, flowers, and twelve-packs live. All of it has to reach the same dock within minutes of each other, because the van leaves at 4:10 whether the yogurt is ready or not.
Deciding who picks what, in which order, and when is the job of a warehouse execution system. Most warehouses already have a warehouse management system that knows what needs to happen. The WES decides how it happens, minute by minute, across every person and machine on the floor.
What is a warehouse execution system?
A warehouse execution system is software that orchestrates the work inside a warehouse in real time. Logistics Management describes it as the layer that "sits between the WMS layer that manages warehouse transactions and manual workflows and the traditional warehouse control system (WCS) that controls and monitors automated systems."
In practice, a WES takes the orders the WMS has released and turns them into tasks: which robot fetches which bin, which picker walks to which aisle, which tote goes to which packing station, and in what sequence. Then it keeps re-deciding as the day changes. A picker calls in sick, a grid port slows down, a rush of orders lands at 11 a.m., and the plan adjusts.
The same article puts the value plainly: a WES coordinates "automated and non-automated workflows around service levels," using functions like "automation-aware order release and synchronization of tasks."
WES vs WMS vs WCS: what does each system do?
The three acronyms get used loosely, so here is the short version.
| System | Main job | Typical questions it answers |
|---|---|---|
| Warehouse management system (WMS) | Inventory, locations, and transactions | What stock do we have, where is it, what came in, what went out? |
| Warehouse execution system (WES) | Real-time orchestration of work | Which order do we release now, who or what picks it, and in what sequence? |
| Warehouse control system (WCS) | Control of automated equipment | How does this conveyor, shuttle, or robot carry out the task it was given? |
Gartner analyst Dwight Klappich put the test well in a 2021 interview with Modern Materials Handling: "the key with a WES is how well it allocates and manages work for the warehouse environment considering multiple resources and constraints including labor, inventory, and the automation."
Some vendors fold WES functions into the WMS, and some put them in the automation controller. Whatever the label, the test is whether one system can see people and machines at the same time.
Why does grocery need a warehouse execution system?
Because a grocery order is several orders pretending to be one.
A general-merchandise fulfillment center might ship a phone case and a pair of socks in one box, picked from one storage area, with a delivery date two days out. A grocery order mixes ambient, chilled, and frozen goods, plus fresh items that are usually picked by hand. It has to come together by a cutoff tied to a customer's delivery slot, often the same day. If the frozen part is ready twenty minutes early, it sits and warms. If the produce is twenty minutes late, the route leaves without it, or leaves late.
That makes timing the main problem. The WMS can say an order needs 30 items from five zones. The WES has to make those five zones finish together, and it has to do that for thousands of orders at once, each with its own departure time.
Grocery automation adds a second problem. Robotic systems are excellent at the products that fit in a standard bin and poor at a sack of potatoes. So most automated grocery sites are hybrid by design, with a grid for the cube-storable range and manual zones for fresh, bulky, and awkward items. Someone, or something, has to keep the robots and the people working to the same clock.
How does a WES coordinate robots and manual picking?
In practice, it comes down to four functions.
Order release. The WES decides when each order enters the floor, based on its delivery slot, its route departure, and the capacity of every zone it touches. Release too early, and chilled goods wait at the dock. Release too late, and the route waits for the order.
Task allocation. Each order is split into tasks for the grid, the manual zones, and any robotic picking cells. The WES assigns them to whichever resource can finish on time, and it rebalances when one zone falls behind.
Consolidation. Totes from the grid and bags from manual zones have to meet. The WES tracks every container, so the order can be assembled once and checked once.
Real-time re-planning. The day never goes to plan. A good WES re-prioritizes within minutes, so a late truck or a slow port changes the sequence instead of breaking it.
What results can you expect from a WES and automation?
The software and the hardware work as a pair, so most published numbers describe both.
The productivity gap between manual and automated picking is wide. In its analysis of online grocery fulfillment models, McKinsey put a warehouse-in-store operation at 80 to 100 units picked per hour, against 400 to 500 for a robotic micro-fulfillment center. Those robots only hit that rate when the software feeds them the right bins in the right order.
BCG's 2026 work on grocery automation describes the change in waves. AI applied to forecasting, routing, and substitution cuts inefficiencies by 10% to 20% in the near term. Robotics and micro-fulfillment could cut picking costs by 30% to 50%, on a five-to-ten-year horizon.
The market is moving in that direction, slowly. Interact Analysis, as cited by Logistics Management, expected more than a quarter of warehouses (26%) to be automated by 2027, up from 14% a decade earlier. Read the other way, about three in four warehouses will still run mostly on people. Mixed operations will be the norm for a long time, which is where a WES earns its keep.
What should you ask a WES vendor?
Here's what I'd want answered before signing.
Does it plan people and machines in one model? If manual zones live in a different system from the grid, consolidation turns into phone calls between zones.
Is it hardware-agnostic? You may add robotic picking or a second automation type later. The WES should take that as a configuration change.
How fast does it re-plan? Ask for an example from a live site, with timestamps.
Does it know about delivery slots and routes? In grocery, the departure time is the deadline. A WES that releases orders without knowing when the van leaves is guessing.
Can it handle temperature and expiry rules? First-expiry, first-out picking and temperature zones should be rules the system enforces at every pick.
How are updates deployed? Some systems need downtime for new releases. In a same-day operation, there is no good time for downtime.
Questions operators ask about warehouse execution systems
Do I need a WES if I already have a WMS?
If you run automation alongside manual picking, or more than one type of automation, usually yes. A fully manual site with simple flows can often manage with a WMS alone.
Is a WES the same as a WCS?
No. The WCS controls equipment. The WES decides what work the equipment and the people do, and when.
Can a WES work with AutoStore™?
Yes. The WES sends tasks to the grid and receives bins at the ports, alongside the tasks it sends to manual zones.
Does a WES only matter for large fulfillment centers?
No. Smaller hybrid sites and micro-fulfillment centers often gain the most, because every minute of misaligned picking shows up in a tight delivery window.
One clock for the whole floor
The warehouses that run same-day grocery well treat the delivery slot as the deadline for everything upstream. Orders enter the floor when the route needs them, grids and people finish together, and the bags meet the van on time.
That's what Veloq's warehouse execution system is built to do, working with the Veloq WMS that runs every Rohlik Group fulfillment center, manual and automated. In Vienna, the system runs a fulfillment center with more than 20,000 SKUs across seven temperature zones, and according to AutoStore, it was the first AutoStore™ grid in the world to integrate real-time expedition inside the grid, with a 30-minute order-to-route time.
The yogurt still has to be ready by 4:10. The WES is how it gets there. See how Veloq's WES works.
Sources
- Logistics Management, "Warehouse execution system: blending human-centered workflows with automation" (July 8, 2024)
- Modern Materials Handling, "WES: It's for warehouse automation and more" (March 26, 2021)
- McKinsey & Company, "Achieving profitable online grocery order fulfillment"
- BCG, "The Race to Automate the Last Mile of Grocery Deliveries" (May 5, 2026)
- AutoStore, "AutoStore and Veloq partner on new Vienna fulfilment centre" (October 17, 2025)
- Veloq, "Profitable Same-Day Grocery Delivery: Lessons from Rohlik Group and Veloq"
