Warehouses, price lists and batches: how they work

The maintenance warehouse is where a company loses money without noticing, and where things get oversimplified most when comparing software. “Stock control” shows up on every spec sheet; what actually changes the outcome are three specific things: how many warehouses you can have and how you value what’s inside them, how the price gets calculated in each case, and whether you can trace a batch.

Several warehouses, including the van

Almost no operation has just one warehouse. There’s the central one, one per branch, and — the one that never shows up in any system — each van’s, where a good chunk of the material actually lives.

In warehouses and items a warehouse can be linked to a client, an address, a supplier, or a team of technicians. That flexibility is what lets you represent reality: the client’s warehouse where you leave material on deposit, the supplier’s that stocks you, and each technician’s van.

Registering the vans is the change that squares an inventory fastest. As long as material that travels isn’t in the system, the system’s stock and the real stock will always be two different things.

And transfers between warehouses record who requested them and who approved them. That double sign-off turns a movement into a reliable data point: without it, whatever leaves the central warehouse and doesn’t arrive anywhere is a discrepancy nobody can explain.

How what’s inside gets valued

Here’s a decision almost nobody asks about in a demo, and it determines the cost you’ll see on every work order.

Each warehouse has its own valuation method, and in GMAO CLOUD there are four:

• Weighted average cost, the default.
• Actual cost, that of the specific entry.
• FIFO, first in, first out.
• LIFO, last in, first out.

It matters because the purchase price of the same reference changes between orders. If you value at average cost, the cost of the intervention smooths out; if you value at actual cost or FIFO, it reflects what that part actually cost. Neither is better in the abstract: it depends on whether you need to compare across periods or allocate with precision.

What is a mistake is not knowing which one you’re using.

Consumption, which isn’t a separate entry

The idea that everything else rests on: in a CMMS, material consumption is a consequence of closing the order, not a follow-up administrative task.

The technician consumes the item from the work order itself in the app, and that single action does two things at once: stock goes down and the cost of the intervention goes up. It works offline, because material gets used in basements and plant rooms.

If consumption gets logged on Friday, the system’s stock has been wrong all week, and the cost of closed orders is incomplete.

The item, with what it takes to work

Each reference carries its cost price and its sale price, its code, its original reference, its brand and model, its unit of measure, and its minimum stock.

Two of those fields matter more than they look. The original reference is what lets you find another manufacturer’s equivalent when the original part has weeks of lead time. And the minimum stock is what warns you before you run out of a part that a job depends on: an inspection that can’t be done for lack of material is an inspection not done, with a paid trip out and a second visit ahead.

There’s also a no stock control flag for consumables not worth counting. It matters just as much as the above: a system that forces you to inventory screws gets abandoned within two weeks.

Price lists: three ways to calculate price

The sale price is rarely just one. There are clients with agreements, item families with discounts, and suppliers with negotiated terms.

In a price list, each item’s price can be calculated three ways:

• Percentage increase or decrease over the base price.
• Fixed value.
• Custom function, for cases that don’t fit the two above.

And a percentage discount can be applied per line. There are also discounts by item family and client, which is the usual way terms get agreed: “for this client, a percentage off the entire spare-parts family,” without having to touch reference by reference.

Supplier prices

The other direction. For each item, a price per supplier is defined, with its own cost, its negotiated discount, its supplier reference and price list, and one of them marked as the default.

The practical consequence is that when a purchase order is generated, the agreed percentage is applied without anyone having to check a commercial agreement somewhere else, and delivery notes stop needing a line-by-line review.

Batches, which are traceability

Not every spare part is eternal or interchangeable. Consumables, liquids, adhesives, batteries, refrigerants, and much of the electrical material has a date.

Items that need it are managed by batch, with its code, quantity, manufacturing date, expiration date, and its own cost and sale price per batch. That last detail is what lets you value stock correctly when the purchase price has changed between orders.

And batches are located within warehouses, so you know exactly which batch is where.

In sectors with strict traceability requirements — food, healthcare, pest control, air conditioning with fluorinated gases — this isn’t a bookkeeping nicety: it’s how you answer which batch was applied at which site and on which day, which is exactly what gets asked when something goes wrong.

What to look at next

The reports on materials used on job reports, asset movements, and inventory answer two questions that tend to be surprising.

Which references actually move, versus the ones that have sat still for two years taking up money on a shelf. And which assets consume the most material, which is another way to spot the machine that should probably be replaced.

That’s also where the short list of what’s worth keeping in stock comes from — it isn’t guessed, it’s inferred from the history after a few months.

If there’s an ERP in the mix

The rule that avoids nearly every problem is agreed before connecting anything: the ERP owns items and price lists; the CMMS owns consumption. Items carry their ERP identifier precisely for that, and so do warehouses.

The integrations catalog lists the scope of each connector, which isn’t the same for all of them.

Where to start

Not by inventorying everything. Start with the references that stop a job if missing — usually fewer than a hundred — with their minimum stock and cost. Then register the vans as warehouses. And do the physical count last: if it’s done before the records are fixed, it’s off again within two weeks.

If you want to see it with your own references, you can request a demo.