Mismatched units of measure: pieces, cartons, sets and kilograms

Head office reports in pieces, the warehouse count sheet is in cartons and the accountant keeps 1C in sets. One consignment, three people, three figures, so the reconciliation naturally fails. Mismatched units are one of the most common and most overlooked sources of difference between books and stock. The numbers are not wrong; each side simply uses a different ruler. It can be fixed once and for all: agree the rules first, then clean the data.

Where the differences come from

• Purchasing is in cartons, sales in pieces and stock in sets, and the conversion exists only in one person's head.
• One item has two units in the system, and someone picked the wrong one when entering it.
• The packing changed: old batches hold 10 pieces per carton and new ones 12, but the system keeps a single conversion factor.
• Steel, cable and bulk materials are sometimes measured by weight, sometimes by length and sometimes by pieces.
• A complete set is stored in parts, so the books show 1 set and the floor shows several components.

These cases share one trait: the difference is often an exact multiple, such as exactly 12 times or exactly 20 times. When you see one, suspect the unit before you suspect a person.

Fix a base unit first

Give each item a single base unit, the smallest unit that cannot be split further, such as piece, metre or kilogram. All book quantities, counted quantities and reconciliation figures are converted to the base unit for comparison. Packing units such as cartons, pallets and sets are used only for entry and display, never for comparison.

Principles for choosing a base unit:

• take the smallest level that can physically be counted on its own;
• keep it consistent with the main unit in 1C or the ERP, and if it differs, state this in the mapping table;
• once fixed, do not change it casually. Any change needs finance confirmation and a recorded date.

Building the conversion table

Each row of the conversion table covers one item and should contain: item code, name, base unit, packing unit, how many base units one packing unit holds, gross and net weight where relevant, and an effective date. An item with several packings gets one row for each.

Take the data from three sources: system unit settings, packing details on orders and packing lists, and the real packaging. Where they disagree, the physical goods win, and finance is told to correct the system. Print the table and keep it on the counting desk for quick reference.

An invented example: an LED panel is booked in 1C in pieces, with 480 pieces in the books. The count sheet is in cartons and shows 24 cartons of 20 pieces each. 24 times 20 is 480, so the two sides actually agree, and the apparent "difference of 456" came only from subtracting 24 cartons from 480 pieces. With a conversion table, differences like this never appear.

Sets and loose parts

Sets need one more rule: first define which parts make up a set, then decide whether the books record sets or parts. At the count, count the parts and convert them into complete sets.

Here is a second invented example. An air conditioner set consists of 1 indoor unit and 1 outdoor unit, and the books show 150 sets. The count finds 151 indoor units and 149 outdoor units. That gives 149 complete sets and 2 indoor units that cannot be paired for now. Report it as "1 set short, with 2 indoor units held separately", and not simply as 150 sets agreeing.

Checking historical data

Once the table exists, look back through past records for errors already in them:

• whether the unit of an item changed at some point;
• lines where document quantity multiplied by packing size is clearly out of line;
• lines whose quantity is an exact multiple of 10, 12, 20 or 24 yet is treated as pieces;
• lines with an empty unit field or a vague unit such as "lot".

List these, confirm each with finance and the warehouse, and record every change.

In short

When units are aligned, many "differences" disappear by themselves. Before counting, UzWarehouse aligns units of measure, item codes and the cut-off date, so that the same goods do not carry different names or different rulers on each side.