Unit of measure (UOM) conversion is translating the quantity on a customer order into the unit your systems actually sell and ship in. A retailer may order in eaches while you sell in cases, or order by weight when you stock by pack. Conversion turns one into the other.
It sounds mechanical, but UOM mistakes are among the most common and most expensive errors in wholesale order processing. Getting the number right and the unit wrong means shipping twelve times too much, or too little.
Common units in distribution
| Unit | Meaning |
|---|---|
| Each (EA) | A single sellable item |
| Inner pack | A small grouping inside a case |
| Case (CS) | The standard shipping unit |
| Pallet | A full pallet quantity |
| Weight | Kilograms or pounds, used for catch weight items |
| Volume | Litres or gallons |
A single product can carry several of these at once. One case might hold four inner packs of six units, giving three valid ways to express the same order.
Why UOM errors happen
The unit is implied, not written. An order line that says “10” relies on everyone assuming the same unit.
Customers order in their own unit. A store thinks in shelf units, while your warehouse picks cases.
Pack sizes change. A supplier moving from 12 to 10 units per case invalidates old assumptions.
Habits differ by customer. The same text means cases for one account and eaches for another.
Conversion factors go stale. If the pack size in the ERP is out of date, every conversion built on it is wrong.
What UOM errors cost
A wrong unit does not produce a small error. It produces an order that is out by the pack factor:
- Ordering 10 cases when 10 eaches were wanted means a store receives roughly twelve times too much
- Ordering 10 eaches when 10 cases were wanted leaves shelves empty and triggers an urgent reorder
- Either way the result is a return, a credit, a redelivery or an emergency top-up
Catch weight items add a further layer, because the invoiced quantity depends on the actual weight shipped rather than the number of units.
Handling UOM conversion well
Store conversion factors centrally. Keep each product’s pack hierarchy in one place so every system uses the same factors.
Map per customer. Record which unit each account orders in, and apply it as a default.
Flag unusual quantities. A quantity far outside that customer’s normal range is often a unit error rather than a genuine change.
Confirm the unit explicitly. Order confirmations should state cases or eaches, not just a number.
Remove manual conversion. Asking reps to convert in their heads under time pressure guarantees occasional errors. Approaches to removing that step are covered in this guide to data entry automation.
How Ordana helps
Ordana resolves the unit of measure as part of reading each line, rather than leaving it to a rep’s judgement. The Ordana Desk Agent uses the product’s pack hierarchy in your ERP together with that customer’s ordering history to work out whether a quantity means cases, packs or eaches.
When a line sits outside the customer’s normal pattern, the agent treats it as a possible unit error and checks with the buyer rather than processing it. The confirmed order states the unit explicitly, so the retailer sees what is coming before it arrives. Because every conversion runs against live ERP data, a pack size change takes effect on the next order rather than waiting for people to notice.
Schedule a demo to see how Ordana handles units on your orders.
Frequently asked questions
What does UOM stand for?
Unit of measure, which is how a product’s quantity is expressed, such as each, case or pallet.
What is a conversion factor?
The number of smaller units in a larger one, such as 12 eaches per case.
Why do UOM errors cost so much?
Because the error scales with the pack size, so a single mistake can be out by an entire case or pallet quantity.
How can UOM errors be prevented?
Keep pack data current, record each customer’s usual unit, flag unusual quantities and state the unit on every confirmation.
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