In this guide 6 sections
Stock differs from the shelf when the ERP hears about a movement late, wrongly or never, so the count sheet and the system report disagree. The usual culprits are draft goods receipts, negative stock allowed, carton to piece conversion errors, skipped batch and serial entry, and transfers left open in transit. Each needs a setting and a habit.
Start by sorting the gap, not fixing it
Take the count sheet and the system report for one warehouse, then mark every item as short, over or matching and rank them by value, not quantity. One gearbox outweighs a thousand screws.
Open the stock ledger for each of the top five and read every line since the last good count, watching for a draft receipt or an open transfer. The cause shows in the sequence. Post no adjustment yet. An adjustment buries the evidence.
- Count sheet with date and time of the count
- Stock ledger for each item since the last count
- Open goods receipts and unbilled deliveries
- Transfers still marked in transit
Goods that arrived but were never posted
The top cause is a draft receipt. The truck unloaded and the racks filled, yet nobody pressed submit, so the shelf holds pallets that the system has never heard of.
The reverse also happens. An early delivery note, or a sales invoice that cuts stock a delivery note already cut, leaves the system showing less than the bin holds.
List every draft goods receipt and delivery note each evening, make the stores clerk own that list, and stop invoices from updating stock whenever a delivery note exists. Putaway lag adds to the gap, since pallets can sit on the dock for a day before anyone scans them into a bin.
Settings that let wrong numbers through
Negative stock is a setting. Allowing it lets sales post before receipts. The balance dips below zero, the receipt arrives and the numbers look fine, but the cost booked on that sale stays wrong until someone reads the month-end valuation report.
Unit of measure conversion is another trap, because an item bought by the carton and sold by the piece needs a conversion factor. Enter a carton of twelve as one, and a pallet of forty cartons leaves the system short by four hundred and forty pieces.
Check the conversion table against the pack sizes printed on supplier invoices, then switch negative stock off for every item except a short list agreed with finance. Small settings, big drift.
- Allow negative stock: off by default
- Conversion factor: match the pack size on the bill
- Valuation method: FIFO or moving average, one per item group
- Reorder level: set only after counts are trusted
Batch, serial and transfer slips
Batch and serial items fail quietly. When a user picks any batch to get past the screen, the right batch shows stock that is missing and the wrong batch loses stock it never held. Totals still agree. Batches do not. Serial numbers fail the same way.
Transfers between warehouses go wrong when the issuing side posts and the receiving side does not, so stock sits in a transit location that nobody counts. Vans and staging racks hide it.
Run a transit report every week, and let anything older than two days earn a phone call to the receiving storekeeper at the destination site.
Make the count and the ledger agree and stay agreed
Once the causes are fixed, post the adjustment with a reason code on each line, and keep the codes few: damaged, miscount, unposted receipt and unit error. Review them monthly. Train against the biggest one.
Switch to cycle counts. Count fast movers weekly, slow movers quarterly and high value items monthly, then let a small daily count catch errors while the paperwork is fresh. The person who slipped still remembers.
Pick one warehouse this week. Run the ledger review on it.
Stock variance investigation sheet
One printed row per item. Columns hold item code, system quantity, counted quantity, difference, value of difference, suspected cause, ledger line reference, fix applied and owner, with space for a second counter’s initials. A header records the warehouse, count date and counter, and the footer lists the four reason codes for adjustments: damaged, miscount, unposted receipt and unit error.
Open a blank worksheet to printQuestions owners ask
Should I just adjust the stock to match the count?
Not before you read the ledger. An adjustment fixes today’s balance and leaves the cause in place, so the same gap returns next month, then the month after.
How often should I count stock?
Count fast movers weekly. Count the rest by value and speed. Short regular counts catch errors earlier than one large yearly count, and they disturb the shop floor less, which matters in a warehouse that ships orders all day.
Why does the total match but the batches do not?
Users likely picked any batch. Set batch selection to follow expiry order, and train the picking team to read the batch label before they confirm each line.
Can software stop negative stock?
Yes. Most ERPs have a setting that blocks any issue larger than the balance, so turn it on once receipts are posted on the day they arrive.