Having a perfect inventory in your warehouse is not difficult. You don’t need to make rotative inventories, nor ask your staff for any extra effort. It is for free.
Install a WMS. You will not only know always how much you have, but where do you have all your goods.
Try to reduce 33 units of the stock of an article in your ERP, you can do it, calm down. If you try to make the same thing in your WMS, you won’t be able to, unless you specify where do you want to subtract those 33 units from.
With an WMS you will never forget a put away or an entry, the worker register it in his wireless terminal or not, and you will change exact inventories to fight for no steals.