When the case size changes, the pieces stay the same

Stock can grow without anything moving. Nobody received anything. Nobody counted anything. Somebody changed a number on the product, and the warehouse suddenly has more of it. That is the quietest way a system lies, and it comes from a place most operators never look: the pack factor.

What a pack factor is

A pack factor says how many base pieces are in one pack. A case with a factor of 24 holds 24 pieces. A dozen holds 12. A master case holds however many cases fit in it, times the case factor. The factor is the bridge between the unit people handle and the unit the ledger counts in.

Every product has one unit of account, the base unit, usually pieces. The factor converts the handling unit into that unit. Two dozen is 24 pieces because the dozen factor is 12. Three cases at a factor of 24 is 72 pieces. The arithmetic is small. The consequences are not.

Why changing one can inflate stock

Many systems store stock in the handling unit and convert on read. The shelf holds 4 cases. The screen shows cases times the active factor. With a factor of 24, the screen shows 96 pieces. Change the factor to 360, and the same 4 cases read as 1,440 pieces. Nothing moved. Nothing was received. The number moved because the ruler changed.

Take a fictional product, SKU BRK-2210, with 4 cases sitting on the dock and an old master case of 24. The screen reads 96 pieces, and that is correct. Now someone adds a master case conversion of 360, because the supplier repacked. Without protection, the same 4 cases would read as 1,440 pieces the moment the conversion is saved. A picker would be sent to pick stock that does not exist. A channel would be promised stock that does not exist. And the ledger would show no movement, because no movement happened. The lie has no author.

The fold: convert before you change the ruler

DockingWare folds before it changes the ruler. When a case or master-case conversion is created, changed, or removed in a way that changes the resolved factor, the system first converts every safe case bucket at the old factor: cases go to zero, and pieces grow by cases times the old factor. Then it writes the new conversion. Then it records one fold event per product, with the before and after for each bucket.

For BRK-2210, the fold turns the 4 cases into 96 pieces at the old factor of 24, and only then writes the new factor of 360. The piece total stays 96. The physical quantity never changed, so there is no inventory movement: a movement says something moved, and nothing did. The fold event is the record that the conversion happened, with the before and after, so a later audit can see exactly what changed and why the buckets look different.

The fold also knows when not to run. An open document line in cases that cannot be folded blocks the change with a refusal: an issued or partially received purchase order, a confirmed ASN, a sales order that is no longer a draft, an open pick, pack, or ship task. Draft lines are folded along with the stock. Closed history stays in cases and does not block. The rule is simple: never rewrite a number a live document depends on, and never let a factor change silently rewrite the stock underneath it.

Why every movement records what was entered

The fold protects the present. The movement record protects the past. Every new movement stores the quantity that was actually entered, the unit it was entered in, and the factor used when the base quantity divides evenly. A receipt of two dozen reads as 2 DZ x 12 = 24 PCS, and that is what the ledger keeps: the entry as the operator made it, and the conversion that turned it into pieces.

That matters because factors change. A movement recorded only as 24 pieces loses the fact that it arrived as two dozen. A movement that keeps the entered unit keeps its own explanation. If the dozen factor changes next year, last year’s receipt still reads as two dozen, and nobody has to guess what the operator meant.

The piece total is the truth. Packs are how people handle the truth: by the dozen, by the case, by the master case. Change the handling, and the truth should not move. The fold makes sure of that on the day of the change, and the entered unit on every movement makes sure of it for every day after.