Ask any operations manager if their inventory numbers match physical count, and you will get one of two answers. "Yes, we do a full count once a year and it is close enough" or "no, we have a variance we just live with." Both answers are wrong, and both are common.
Inventory drift is usually small and invisible day to day. You ship a unit without scanning it. You receive a pallet and count 48 when it is actually 47. You move stock between locations and forget to update the system. None of these alone is a disaster. All of them together, over 12 months, is a financial reporting problem.
The consequences show up in unexpected places. You go to fulfil an order and the system says you have stock, but you do not. You build a purchase forecast on wrong numbers. Your auditor finds the variance at year end and asks uncomfortable questions. Your customers get backorders when the website said "in stock."
The traditional fix is cycle counting. You count a portion of your stock every day so the whole warehouse gets counted several times a year. It works but it is labor-intensive and most teams skip it the moment they get busy, which is exactly when the variance starts accumulating.
The modern fix is to instrument every movement. Every receive, every ship, every transfer, gets a scan, and the scan hits the system in real time. This sounds obvious, but many ops teams still have a gap where someone writes it down and enters it later. Every minute between the physical event and the system event is a minute the data can go wrong.
The other piece is exception detection. If the system is getting fed clean data in real time, then when something deviates from expectation, it pops out immediately. A count that does not match the expected shipment. A location that has stock showing but no receive history. These exceptions are where the 1 to 2 percent drift hides, and they can be surfaced automatically for a human to investigate.
Most ops teams we work with reduce inventory variance from 3 to 5 percent down to under 1 percent in the first six months. The money that shows up on the balance sheet is not a small number. The confidence in the numbers is worth more, because it means every downstream decision is built on a real foundation.