Amazon was actually utilizing randomized storage before they implemented the Hercules robots. In the traditional FCs the inventory was randomly scattered throughout the shelves for the same reason it is randomly scattered throughout the pods: to minimize the likely walk time for any given order picker. What the Hercules system allowed them to do was replace human walking time with robot rolling time and to condense the inventory footprint by eliminating walkways.
I'm not as familiar with the Proteus system but my guess on why Amazon would prefer it to belts is that it takes up less space than a belt system, if a single Proteus robot fails the rest of the system keeps operating (unlike a belt where a failure anywhere along it shuts down the whole thing), and if each package needs to be hand placed on a Proteus the likelihood that two packages gets placed (the most common missorting error) would be reduced.
Amazon was actually utilizing randomized storage before they implemented the Hercules robots. In the traditional FCs the inventory was randomly scattered throughout the shelves for the same reason it is randomly scattered throughout the pods: to minimize the likely walk time for any given order picker. What the Hercules system allowed them to do was replace human walking time with robot rolling time and to condense the inventory footprint by eliminating walkways.
I'm not as familiar with the Proteus system but my guess on why Amazon would prefer it to belts is that it takes up less space than a belt system, if a single Proteus robot fails the rest of the system keeps operating (unlike a belt where a failure anywhere along it shuts down the whole thing), and if each package needs to be hand placed on a Proteus the likelihood that two packages gets placed (the most common missorting error) would be reduced.