Robots and Your WMS

Draw the software layers before choosing interfaces

Many sites run three software layers. The warehouse management system holds stock, orders and locations. An execution or control layer, often called a WES or WCS, sequences the work and talks to equipment. The robot maker's fleet manager assigns individual robots, plans their routes and handles charging. Before talking to suppliers, sketch which layer will own each decision: which order is released next, which tote goes to which station, which robot takes the job and who confirms that stock has moved. Gaps and overlaps in that sketch are where integration costs grow, because someone will have to write custom logic to fill them.

Use VDA 5050 for vehicle-level messages

VDA 5050, published by the German automotive industry association VDA with the machinery association VDMA, defines an interface for exchanging order and status information between automated guided vehicles and a master control, using MQTT and JSON messages. Version 2.1.0 is dated January 2025. It covers orders, vehicle state, actions such as pick and drop, maps and instant commands. Just as important is what it leaves out: the document places integration with warehouse management and enterprise systems, and with peripherals such as gates, lifts and fire protection, outside its scope. Ask makers which version they support and test their messages against your own scenarios.

Watch ISO 21423 for mixed fleets

Where robots from several makers share a floor, a common interface between fleets matters more than any single vehicle protocol. ISO 21423, Robotics: industrial mobile robots, communications and interoperability, sets out communication protocols so that industrial autonomous mobile robot systems from different vendors can work together, covering the robots, fleet manager equipment and the enterprise resources that talk to them. ISO's catalogue showed it at the publication stage in October 2026, and it does not address safety requirements. When you write a specification, ask suppliers how they plan to support it and whether their fleet manager can share traffic and space with another vendor's robots.

Clean master data before the robots arrive

Robots act on the data they are given. A 2023 Chalmers University of Technology master's thesis on moving from manual to automated warehouse operations found that automated operations rely on correct master data to run without standstills, and that standardising processes before automation made implementation easier. It also warned that adding third-party applications to an existing WMS could cause synchronisation problems. Audit item dimensions, weights, units of measure and location records before integration testing begins, and fix scanning habits that create wrong entries. Agree who corrects the data errors that robots expose, and how quickly, because each bad record turns into a stopped task on the floor.

Sources and further reading

• VDA 5050 Version 2.1.0: Interface for the communication between automated guided vehicles (AGV) and a master control — Verband der Automobilindustrie (VDA) and VDMA.
  The published interface for order and status messages between vehicles and master control, including what it leaves out.
• ISO 21423 Robotics: industrial mobile robots, communications and interoperability — International Organization for Standardization (ISO).
  Catalogue entry for the new standard on communication between mobile robot fleets from different vendors.
• Investigating requirements for introduction of automated warehouse operations (master's thesis, 2023) — Chalmers University of Technology.
  Case study on how WMS needs change when a warehouse automates, with findings on master data and add-on software.

Common questions

Do I need a new WMS to use warehouse robots?

Not always. Robot fleets often connect to an existing WMS through an interface or execution layer, but older systems may lack real-time task messages or clean location data. Test the interface with your own order files before deciding to replace any software.

What is the difference between a WMS and a WES?

A warehouse management system manages inventory, orders and locations. A warehouse execution system sits closer to the floor, releasing and sequencing tasks across people, robots and conveyors in near real time. Some products combine both roles, so check which functions your current software already covers.