Meet the fast 3D storage solution that boosts logistics

So-called cube-storage systems have been in the automated material handling market for over ten years now. They are very popular and for good reasons. Cube-storage solutions are very compact, reasonably affordable and offer an efficiency increase in order fulfillment.
 
A cube-storage system typically has products stored in bins and those bins are stacked on top of each other in a metal structure. Robots drive on top of the grid (or, in some solutions, below the grid) to retrieve the bins. In most cases, if a bin somewhere in the middle of a stack is required, all bins on top of it are placed to the side by robots that“dig out” the required bin. This technology makes efficient logistics and order fulfillment possible in distribution centers, taking warehouse operations to another level.

All this works very well, up to a limit. That limit is defined by the “storage-to-throughput ratio”. The throughput of these systems is limited by the number of robots that fit on (or below) the storage and retrieval system. Use too many robots, and the operation will get congested.  
 
In the last ten years, this limit has increased. In the beginning, the maximum throughput that could be achieved in a system storing 10.000 bins was around 600 to 700 bins per hour. For a system with 20.000 bins, that would be double, etcetera. 
 
Smarter Warehouse management systems (WMS), or Warehouse Execution systems (WES), faster robots and better layouts have increased this limit significantly, but there is still a maximum that can be achieved. The only thing that could be done to reach beyond that is to make the cube system lower. That will increase the surface area to create more space for the robots to navigate the system with more efficiency.

In real-world and real-time terms, what do these numbers mean? Let’s assume an average bin holds 30 pieces. And that for each bin presented, you pick out two pieces. With an average of 8 hours of picking per day, this would equal 15 to 30 days of inventory in the system. Or a stock rotation of 10 to 20 times per year.
 
For many warehouse operations, this is more than enough. A lot of them will never be close to this limit.

What if it would be possible to get the performance of a shuttle with all the advantages of a robotic cube-storage solution? Canadian company Attabotics has come up with that solution. 
 
Inspired by how leafcutter ants build their colonies, they created a true 3D storage and picking solution. In this solution, the robots do not only travel in two dimensions, but they can also move vertically. This gives them access to each bin without the need for digging. It also provides more space for the robots to drive above the system, below or in the vertical shafts. It also makes it possible to build taller systems without scarifying performance in the distribution centers. Because of this, the theoretical limit of storage vs. throughput is 5 to 10 times higher than most other cube storage systems.