Sorting goods with an industrial robot arm: Robot scheduling, destination assignment, and layout design

Sorting goods (e.g., picked products according to customer orders or parcels according to outgoing destinations) is an elementary task in almost any warehouse and distribution center. A novel sorting system based on an industrial robot arm promises a fast and space-efficient sortation process. Located at the center of the circular system, the robot fetches goods from one of multiple infeed conveyors and puts them into bins or chutes arranged around it. This paper treats this sorting system from an operational research perspective, addressing all elementary decision tasks. We start with the operational scheduling problem, where we optimize the robot’s pickup sequence of the arriving goods on the conveyors. Furthermore, we address how to assign the sorting destinations to the bins or chutes of the system and the design of the system layout. Our research shows that an optimized system promises a significantly improved throughput performance.