Addressing and marking shelves: how to number a warehouse so that the picker doesn't wander
The cell address is built according to the hierarchy: zone → row → section → level → position. This structure gives each storage location a unique code that is read equally by the worker, the scanner and the WMS.
For example, address A-05-12-03-B refers to specific position B on the third level of the twelfth section of the fifth row in zone A. Sequential addressing reduces product search time and simplifies the introduction of new pickers into work.
How to build a cell address
The code should describe the physical location from the largest storage unit to the smallest. For a single level, the structure zone-row-section-tier-position is sufficient. In a multi-level warehouse, a floor is added, for example M2-A-05-12-03 denotes a cell on the second level of mezzanine shelving.
The product is tied to the address. Thanks to this, changing the assortment or slotting does not require renumbering the warehouse. For mezzanine racks, the floor becomes a separate element of the address. For shelf racks, it is advisable to detail the position on the shelf.
Set the code format to be the same for all zones, for example, two characters for the row number and two for the section. Then A-05-03 and A-15-03 are read using the same logic, and the sorting of addresses in the WMS maintains the correct sequence. Create a separate directory of permissible zone, floor, and item type designations.
How to number rows and sections
Set the numbering direction according to the actual movement of the employee through the zone. If the route starts at the entrance, the first available row is numbered 01, and the sections within it are numbered 01, 02, 03, and so on in the same direction. The next row continues the same logic.
To determine how to number the racks in your warehouse , first confirm the final row and aisle layout. Do the detailed calculation and placement of the racks before printing the labels, as changing the layout also changes the addressing system.
The checkpoint is simple: upon seeing addresses A-05-10 and A-05-12, the picker should immediately understand the direction to the second cell.
What to put on the marking
The label must contain a large human-readable code and a machine-readable barcode with the same identifier. The A-05-12-03-B inscription on the rack, the value inside the barcode, and the entry in the warehouse WMS system must match.
Place the marking where it is clearly visible to the worker and consistently read by the work scanner. For high levels, the main address can be duplicated at an accessible height with a tier designation.
How to maintain the address system after launch
Once launched, keep a record of address changes. For each new section, moved rack, or reconfigured area, record the old code, new code, date of change, and responsible person. This helps to keep labels, WMS, and work instructions up to date and maintain one current address for each location.
When replacing a label, first update the record in the system, then check the code with a scanner, and only then enter the location into operation. For large changes, it is convenient to close one zone at a time: this way, pickers work according to a single numbering scheme throughout the transition.
How to check addressing before launch
Before scaling, test one finished zone on real sampling routes. The sequence is as follows:
Code 20–30 cells.
Prepare 10–20 random addresses.
Measure the search time for each position.
Check barcode reading.
Correct any ambiguous markings and retest.
If the new scheme reduces the cell search by 6 seconds, on 1000 order lines per day the savings are 6000 seconds, or 100 minutes of working time per day. It is the time taken to complete the picking route that shows how well the addressing works in real operations.