Walk into any order fulfillment operation, and you will see gravity flow rack.
The reason is obvious–it’s one of the best ways to pick orders utilizing first-in, first-out principles. It used to be that there was one kind of the stuff, the plastic-wheel tracks, but these days the choices are more diverse than ever. For the most part, these flow rack types act the same; they decline toward the picker and boxes or totes or even larger components flow toward him. They’re restocked from the rear and picked from the front onto a takeaway conveyor line, a cart, workstation, or another step in the process.
Something we often recommend to save space for our clients is 
