In short: a WMS (Warehouse Management System) is the software that keeps stock by location, not just as a total, and records every movement of goods by scanning: receiving, put-away, order picking, dispatch, stock counts. You need one when your invoicing software is no longer enough: several warehouse workers, hundreds or thousands of SKUs, racks on several levels and stock counts that always come out with differences.
What a WMS does and what it doesn’t
Your invoicing software or ERP knows how much stock you have of a product. A WMS also knows where it is: in which warehouse, zone, rack, level and position, in which batch, with which serial number and expiry date. The difference seems small, but it changes the way the warehouse works.
- Receiving: the warehouse worker opens the supplier order on the phone and scans what arrived. Shortages and surpluses are visible on the spot, not at next day’s reconciliation.
- Put-away: every position has a barcode label. The system recommends where to put the goods and keeps track of physical, available, reserved and incoming stock.
- Picking: the order reaches the phone in the order of the route through the warehouse, and scanning verifies every product. A product that isn’t on the order can’t end up in the parcel.
- Dispatch: clear statuses on every order (in progress, picked, loaded), photos of the loaded goods, serial numbers delivered.
- Stock counts: you scan a shelf, see what should be on it and correct the differences, without stopping the warehouse for a whole day.
What a WMS doesn’t do: it doesn’t issue invoices and doesn’t replace accounting. Fiscal documents stay in the invoicing software. The WMS takes the item list and orders from there and sends back what happened in the warehouse.
Six signs you need a WMS
- Every stock count comes out with differences and nobody knows for sure why.
- One person knows where the goods are. When they’re on holiday, orders ship slower or wrong.
- Orders ship with missing or swapped products and you find out from the customer.
- You have products with serial numbers, batches or shelf life and can’t answer on the spot which serial a customer received.
- You have several warehouses or sites and stock is kept in separate spreadsheets.
- Warehouse staff spend more time looking for goods than picking orders.
If you recognise two or three of these, a WMS pays for itself quickly. If you have a small warehouse, one worker and a few dozen SKUs, the stock module of your invoicing software is probably enough.
What a good WMS should include
- Locations in levels: warehouse, zone, rack, level, position, each with a label. The position code should also tell you where it physically is.
- Verified scanning: the system confirms you picked the right product, in the right quantity, rather than just recording what you typed.
- Traceability: batches, serial numbers and expiry dates tracked from receipt to the customer, with FIFO allocation.
- Integration: a connection to your invoicing software or ERP, over API, straight from the database or through files, with no duplicates when syncing.
- A mobile app that works on the phones you already have and on scanner terminals, even without signal in a corner of the warehouse.
- Full history: who, what, when, from where and to where, for every movement.
Phone or scanner terminal?
You don’t have to start with industrial terminals. A modern mobile app installs from the browser on ordinary Android phones and reads barcodes with the camera. Terminals with a built-in scanner read faster and survive drops better, so they make sense at high volumes or in cold halls. Ideally the app works the same on both, so you can start with phones and add terminals when volume grows.
How long implementation takes
The duration depends on the size of the warehouse and the connections to other software, but the stages are the same:
- The workflow conversation. How goods and documents move today, what goes into the first stage.
- Locations and labels. Coding the zones, racks and positions and printing the labels. This is usually where most of the time goes, because it happens physically, in the warehouse.
- Data and connections. Importing the item list, partners and stock, then connecting to the invoicing software, in test mode first.
- Training. Warehouse staff learn on their own phones, with their own goods.
- Go-live and fine-tuning. In the first weeks, rules, labels and reports get adjusted.
A serious vendor gives you a written estimate after the first conversation, not a generic deadline.
What the cost is made of
The price of a WMS usually has four components. Ask about each one separately, so you can compare offers:
- The licence or subscription for the application, sometimes per user or per warehouse.
- Implementation: analysis, configuration, data import, training.
- Integration with your invoicing software or ERP, which depends on what that software allows.
- Equipment: a label printer, possibly scanner terminals and a WiFi network that covers the aisles.
Hosting matters too: in the cloud, on an instance dedicated to your company, or on your own server if you prefer to keep the data in-house.
Frequently asked questions
What is the difference between a WMS and an ERP?
The ERP covers the whole company: accounting, invoicing, sales, purchasing. The WMS covers the warehouse in detail: locations, scanning, picking, stock counts. The two work together: the ERP sends the orders, the WMS sends back what was received and what was delivered.
Can I keep the invoicing software I use?
Yes. A good WMS connects to your existing software and doesn’t ask you to change it. The connection method (API, database or files) is agreed during analysis.
What do I do with products that have no barcode?
You print labels for them with the product’s internal code, from the WMS. Suppliers’ barcodes are linked to products at the first receipt and recognised automatically next time.
Does it work without internet?
The mobile app stays open without signal and keeps scanned serial numbers and photos on the phone until the connection is back. Receipts and deliveries do need a connection, because they change the stock everyone else sees.
How fast does it pay off?
It depends on how many orders ship wrong today and how much time is lost looking for goods and counting stock. Do the maths on your own numbers: returns caused by the warehouse, hours spent on stock counts and picking time per order.
DataFlows Depo is our WMS: it runs on the Android phones you already have and connects to your invoicing software. See what DataFlows Depo does or request a demo.
