One shared item master for several warehouses

Ask three warehouses for their product lists and you will get three files with different columns, different names and, for a few hundred items, different codes. Everyone calls it "the list", yet it is not one list. When a count merges the warehouses, differences between the lists are mistaken for differences in stock. A shared item master removes the cause rather than the symptom.

What belongs in an item master

One row per SKU, holding the facts about the product that do not depend on the warehouse:

• the SKU and its barcodes
• the name or names used by your team
• the unit of measure and the number of pieces per carton
• the category and the supplier
• weight and dimensions, if you use them
• the status: active, being phased out or discontinued

What does not belong there: quantities, bin locations and anything that differs from one warehouse to the next. Those live in the stock table, which looks up the master by SKU.

Required fields and simple checks

Decide which fields must never be empty: SKU, primary name, unit, pieces per carton, category, status, and a barcode or the words "label pending". Then add simple controls:

1. Use drop-down lists for unit, category and status so that "pcs", "pc" and "piece" do not coexist.
2. Highlight any SKU that appears twice with a COUNTIF check.
3. Store barcodes as text, or Excel will drop leading zeros or turn long numbers into scientific notation.
4. Do not let a row become "active" while a required cell is empty.

Add a "last checked" date to each row and review the rows that have not been checked for a year. An item master goes stale as quietly as a price list.

Who may change it

Name one owner and one deputy. Warehouses ask for new items through a short, fixed form: suggested name, unit, pieces per carton and a photo. The owner searches the master by barcode and name to make sure the item does not already exist, assigns the SKU, enters the row and tells everyone. A change log with the date, SKU, field, old value, new value and reason keeps the history. Nobody else edits the master; warehouses get read-only copies.

How the warehouses use it

Each warehouse's stock sheet takes names and units from the master by SKU instead of keeping a private copy. Publish a new version at a fixed time, for example every Monday, with the date in the file name. For a count, freeze one version and tell everybody which one it is. When a warehouse finds a wrong entry, such as a wrong carton quantity, it sends the correction to the owner instead of fixing its own copy, so the fix reaches every site with the next release.

An example with numbers

Suppose three warehouses keep lists of 480, 455 and 510 rows. After merging and removing duplicates by barcode there turn out to be 540 distinct products, and 38 of them carry a different unit of measure in different lists: cartons in one, pieces in another. Those 38 are exactly the products that would show false gaps in a merged count, however carefully the shelves were counted. One master with a single unit per product removes them before anybody picks up a scanner.

Start small and keep one owner

Do not try to design forty columns on the first day. Begin with the required columns for the hundred fastest-moving SKUs, run it for a month and then extend it. A small master that everyone uses beats a large one that nobody trusts. Review the change log monthly: the fields that keep being corrected are the ones that need a rule, a drop-down list or a clearer definition.

An item master can live in a shared spreadsheet or in 1C; the tool matters less than the discipline. The two failures that kill a master are that nobody owns it and that people keep a private copy "just in case". Once a second copy exists, you again have two lists.

InventoryHub builds a code mapping table of supplier, marketplace and book codes before counting, and hands it over so that receiving and the next count can keep using it. It is a good starting point for your own master.