Zero-crossing

Zero-crossing occurs when the stock quantity of an item at a staging location is less than or equal to the pending withdrawal requirement. A distinction must be made between intentional and unintentional N. In the case of intentional N., book inventory and physical inventory are congruent, whereas in the case of unintentional N. they are not.
In perpetual inventory, the “event”; N. is often taken as an impetus to carry out an inventory for this location or article in order to reduce the counting or recording effort to a minimum.

Source: logipedia / Fraunhofer IML