What Is a Location System and Why Does Your Warehouse Need One Before It Grows?

In September, your company leased the building next door to receive year-end inventory, and the team started calling it "the new building." Its aisles were numbered again starting from one, so there are now two "aisle 3, level 2" locations, and much of the merchandise was recorded in the system only as "Warehouse 2." One Tuesday morning, your supplier announces a recall of a lot because of a manufacturing defect and immediately requests every case you have in stock. The system confirms the lot is in inventory but does not show which position it is in. Six people stop picking to check both buildings case by case, and by the end of the shift there are still cases unaccounted for, with no one able to say whether they were put away in the wrong place or have already shipped in orders to your customers.

A location system assigns a unique code to every physical space in the warehouse and records in the WMS which product, lot and quantity it holds. Putting it in place before you grow keeps every new square meter from adding lost inventory.

The warehouse that runs on memory until the day it grows

Almost every warehouse starts with an informal location system. Places are named by habit: the rack next to the column, the shelf with the small spare parts, the floor in front of dock door two. As long as the team is small and stable, that map lives in the operators' heads. The problems appear when the operation grows and the map has to be shared with people, shifts and buildings that do not know it.

Names only their inventor understands

A location named by habit depends on the person looking for it knowing the reference. "Behind the blue pallet" disappears when the pallet moves, and "the screw aisle" confuses everyone the day the screws change places. The new operator asks, the veteran interrupts their work to guide them and picking time depends on who is on shift.

Stock without an address

When the system records inventory only by warehouse, it knows how much there is and has no idea where. The same product can be in five places at once: one in reserve, another in picking, another in the receiving area and two more wherever there was room. Total inventory reconciles, and yet the picker reports a shortage because they checked the only location they knew. Much of phantom inventory starts here, in merchandise that exists and has no address.

Growth breaks the map

A new building, a second shift, a mezzanine or temporary peak-season staff multiply the number of people who need to find merchandise without asking. Every building added with its own naming logic creates duplicate codes, and every duplicate code is an item put away in one place and searched for in another.

What a location system is and how it differs from layout and slotting

A location system is the set of rules your warehouse uses to identify every space where merchandise can be stored, together with the record the WMS keeps of what each one contains. It has three parts: a naming convention, a physical label the scanner can read and a catalog with the attributes of each location.

It helps to distinguish it from two related concepts. The layout defines the warehouse zones and the flow of goods between them; slotting, which we covered a few weeks ago, decides which product is best stored in each position. The location system supports both: it gives every space a unique identity so the layout can be configured in the system and slotting has specific addresses to assign products to.

A naming convention that reads like an address

The most common naming convention goes from general to specific: warehouse, zone, aisle, bay, level and position. A code like 01-A-12-05-C-2 reads like a mailing address: warehouse 01, zone A, aisle 12, bay 05, level C, position 2. Levels are named from the floor up, numbers carry leading zeros so they sort correctly in any list, and one side of the aisle takes odd numbers and the other even numbers, so the sequence of codes follows the picker's route.

Labels the scanner confirms

Each location has a label with its human-readable code and its barcode, always placed at the same point on the rack. On upper levels, larger labels or long-range scanners are used so the operator can confirm the location from the floor or from the forklift. The label turns the code into a control: the operator scans the location before placing or taking merchandise, and the system rejects the movement if the position differs from the one indicated.

The attributes of each location

In addition to the code, the location catalog records what each space can hold: its type, such as pallet position, case shelf or floor area; its capacity in weight, volume or number of pallets; its use, such as picking, reserve, receiving, shipping or quarantine; and its restrictions, such as controlled temperature, restricted access or material compatibility. With that data, the system avoids sending a pallet to a position where it does not fit or a refrigerated product to a rack at room temperature.

What the WMS controls when every location has an identity

Stock by location, lot and expiration date

With coded locations, the WMS records inventory at the level of detail where the work happens: which product, which lot, which expiration date and what quantity is in each position. In a lot recall like the one at the beginning, the query returns the list of locations with their quantities, and the portion that has already shipped appears linked to the orders that carried it.

Every movement confirmed with two scans

Put-away, picking, replenishment and relocations are recorded by scanning the location and the product. Relocations are the movement most often done without a record: an operator frees up space, moves three pallets and the system keeps looking for them in the previous spot. With radio frequency terminals, every movement is recorded at the moment it happens.

Statuses that protect the operation

Every location has a status. A position with a damaged rack is blocked so no one puts goods away in it; a location being counted is frozen while the count takes place; the quarantine zone holds product that the system keeps out of picking until quality releases it. Statuses turn supervisor decisions into rules the system applies on every shift.

Cycle counts by location

With inventory by location, counting no longer requires the warehouse to stop. One aisle is counted each day, the system compares what was counted with what is recorded in each position and the difference is tied to a specific place. That makes it possible to investigate the cause, such as an unrecorded relocation or a put-away in the neighboring position, instead of adjusting an overall figure with no explanation.

Why it pays to put it in place before you grow

Code the warehouse while it is empty

Labeling an empty building takes days; coding a full warehouse requires moving merchandise, taking a physical inventory by location and keeping operations running in the meantime. When your company opens a building, installs a mezzanine or adds a row of racks, it has the least expensive moment to give each position its code, before the first pallet arrives.

A naming convention with room for the next building

The naming convention is designed with the warehouse you will have in a few years in mind. Reserving one segment of the code for the warehouse and another for the zone makes it possible to add buildings, branches or sub-warehouses without repeating codes or renaming what already exists. That segment is exactly what was missing in the case at the beginning, with two identical aisle 3 locations in two different buildings.

New staff who find merchandise without asking

During peak season, temporary staff need to be productive from their first shift. With a location system, the terminal shows them the exact address of each item and validates every scan, and the learning curve comes down to reading codes and following the route sequence.

The mistakes that make coding useless

Catch-all locations that become permanent

Many systems have generic locations such as "receiving," "floor" or "general," useful for recording merchandise in internal transit. The problem starts when they are used for storage: the product stays for weeks in a location that covers hundreds of square meters on the floor, and the system once again knows how much there is without knowing where. It is best to review what is in those locations every day and set a maximum dwell time for them.

Labels nobody maintains

When a rack is moved, a beam changes height or a damaged section is replaced, the label has to move with the location and the catalog has to be updated. A fallen or misplaced label becomes the cause of errors that are later blamed on the picker.

Locations and traceability on an integrated platform

At Oasys, location control is part of the WMS in our platform, which integrates ERP, WMS, TMS and Production on a single database. Put-away is recorded by radio frequency, stock is updated in real time and every unit keeps its traceability by lot, serial number and expiration date. Slotting, picking with optimized routes and physical, cycle and full inventories all run on that foundation.

The platform is multi-company and multi-warehouse, with bonded sub-warehouses, so a new building or a branch is operated in the same system as the others. Everything runs on our own servers, in a data center, and we have spent more than 30 years developing management systems for companies in Mexico.

Frequently asked questions

How long does it take to code a warehouse that is already operating?

It depends on the number of positions and how much inventory has to be relocated. The usual approach is to work by zones: one zone is labeled, its physical inventory is taken by location and it is activated in the system before moving on to the next, so picking keeps running during the transition.

Can I use the same naming convention in several warehouses?

Yes, and it is a good idea. A common format with a segment that identifies each warehouse avoids duplicate codes and lets an operator who moves to another branch read locations the same way. That segment is reserved from the start, before the second warehouse exists.

How do you code merchandise stacked on the floor?

Floor areas are also divided into locations. Lanes are marked on the floor, each one receives its code and a label on a nearby column or on a hanging sign, and the system records how many pallets it can hold. That way, floor-stacked merchandise is as easy to locate as merchandise on the rack.

If finding a case in your warehouse still depends on asking the person who put it away, every building and every new operator you add will multiply the time your team spends searching. At Oasys we integrate ERP, WMS and TMS on a single database, on our own servers, so every location in your warehouse has a code, a status and recorded inventory before the first pallet arrives. Find out how at https://www.oasys.com.mx/en