You can use the word "inventory" and "fluctuate" in one sentence like this:
(1) When they looked at the inventory, they found that the sales fluctuated for the past 3 months.
(2) I think that the company's rank will continue to fluctuate due to failure of looking at the over-all inventory of its profits and losses.
(3) Their opinions about the issue are fluctuating and all are recorded along with the inventory.
(4) No matter how much you analyze this year's profit, you can't stop the sales from fluctuating.