Which method is generally used to improve space utilization in storage facilities?

Vertical storage solutions are recognized as an effective method for enhancing space utilization in storage facilities. This approach takes advantage of the height of a storage area, allowing items to be stored in multiple tiers or levels. By utilizing vertical space, facilities can maximize their storage capacity without increasing the actual floor area, leading to better organization and accessibility of goods.

In contrast, open shelving units primarily offer flexibility and visibility of items but do not inherently improve the ability to store more items within the same footprint. Expanding the facility's footprint can be costly and may involve significant construction efforts, which is not always feasible for improving space utilization immediately. Reducing inventory levels can alleviate overstock issues but does not directly enhance the physical storage capability of the space being utilized. Thus, vertical storage solutions are the most strategic method for improving efficiency in storage facilities.