Many warehouses, in Mexico and elsewhere, run on a carefully built spreadsheet that worked for years. The need to replace it usually arises from a specific event: a second warehouse, more people entering data, an audit or a customer asking for lot traceability. For a US company acquiring or opening a Mexican operation, it often comes on day one, when headquarters requests stock by location and the operation cannot provide it.
This article covers the stage after the decision: how to make the switch without stopping operations. It proposes a six-week plan for a small or mid-size warehouse; a larger one carries it out by zone or by building.
Software is not the longest task
With a cloud WMS, the instance is ready quickly. What takes weeks is organizing the information the system will receive: a catalog with unique codes, coded and labeled locations, and staff trained in their positions. A WMS does not correct inaccurate data; it makes it visible.
Week 1: clean the catalog
A spreadsheet accepts data that a WMS rejects by design:
- Duplicate or reused codes. Each product needs a unique code that does not change. If one code was used for two different products over time, they must be separated.
- Unit of measure. Decide for each product which unit stock is controlled in (each, case, kilogram) and do not mix them. Case-versus-each confusion is one of the most common causes of discrepancies.
- Lot, serial and expiration. Mark which products are lot-controlled, which serial-controlled and which require an expiration date. A product is controlled by lot or by serial number, not both.
- Barcodes. Record the manufacturer's barcode when there is one; otherwise the WMS prints its own labels.
- Discontinued products. Retire products with no recent purchases or sales and do not load them.
In Chainlink WMS, the catalog is loaded with an XLSX or CSV template that shows errors by row and column before creating anything, and an existing code is updated instead of duplicated.
Week 2: code and label locations
Locations are the foundation of a WMS: the system must record where each product is. Define a code structure, for example zone, aisle, rack and level (A-05-03-2), and apply it to the whole warehouse, including receiving, shipping and quarantine areas. The guide on location coding explains the rules that keep codes unique and readable.
Then print and place location labels with barcodes. This is physical work that can be done without affecting operations, in the afternoon or on a weekend. In Chainlink, the generator creates locations by ranges of aisles, racks and levels, and labels print on Zebra printers connected with Chainlink Wizard.
Week 3: configure and connect equipment
Set up users, one per person with their role, label printers and handhelds. At each station, verify that the handheld reads location and product codes and that the printer prints correctly. If orders or purchase orders come from an ERP or an online store, decide how they will reach the WMS: by file, through the API or with a connector.
Week 4: train by position and practice
Train by position, not with a general presentation: receivers learn to receive, pickers learn to pick. Each person practices with their handheld in the real warehouse using test documents. A one-page procedure per position, with photos, settles most first-week questions. In a bilingual operation, Chainlink's Android app and web platform are available in Spanish and English.
Week 5: pick go-live day and prepare the cutoff
Choose a date that meets these conditions:
- Outside peak season. In Mexico, a switch in November or December competes with the year's highest volume.
- At the start of a month. The month-end close then sits entirely in one system.
- With the warehouse in order. Receipts put away, returns resolved and damaged product separated.
Let suppliers and customers know if receiving or shipping will run reduced hours that day.
Week 6: the switch, by zone
On go-live day, opening inventory is recorded. The most reliable way is to count by zone, scanning every location and product, rather than copying quantities from the spreadsheet: that way, the WMS's first record comes from a count and does not inherit past errors.
In Chainlink, opening inventory can be loaded as inbound documents by file, one per zone, with lot and expiration, then received and put away with the handheld. Each scan confirms product, quantity and location.
From that moment on, every movement happens in the WMS. The spreadsheet is kept as a reference and is no longer updated.
Why parallel operation is not recommended
Running the spreadsheet and the WMS side by side for weeks appears prudent, but it doubles data entry, overloads the team and, within days, neither record is correct: every difference requires determining which one is valid. It is safer to prepare thoroughly, switch on a defined date and promptly correct the issues that arise in the first week.
The first four weeks after go-live
- A ten-minute daily review of open documents, short picks and discrepancies.
- Cycle counts of the fastest movers from week two.
- One owner for master data, who creates products and locations under the agreed rules.
Frequently asked questions
How long does it take to move from Excel to a WMS?
For a small or mid-size warehouse, about six weeks of preparation, mostly cleaning the catalog, coding locations and training. A large warehouse switches by zone or by building.
Can inventory be imported from Excel?
The product catalog, yes, with a template. For stock, it is better to count by location on go-live day than to copy quantities from the spreadsheet, so the WMS's first record is a real count.
Must the warehouse stop to change systems?
Not the entire warehouse. Preparation happens without affecting operations; on go-live day, counting and start-up go zone by zone, so only the zone being counted stops for a few hours.
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