Bot-assisted Cluster Picking
Bots with multiple totes or slots allow picking of multiple orders in parallel. Bots move the orders around the picking area, stopping at every location required to fill the order. Human workers do the picking into the appropriate tote or slot. Once those picking tasks are complete, the bot travels to the next location required for the order and the worker travels to the next closest bot. When all of the orders in a cluster are complete, the bot travels to a packing area.

Benefits: Bots increase the productivity of the worker by reducing walking from/to pick up and deposit stations and across zones with no picks. By increasing the productivity of the worker, the distribution center needs less labor, which reduces the costs associated with hiring, training, and retaining workers.

Challenges: Bots operate at a lower speed than humans, and load capacity constraints might limit the number of orders in a bot cluster. Because of these factors, the number of bots in the bot-assisted solution is always higher than the number of human workers in a traditional manual cluster picking operation. Furthermore, bots must wait for pickers to execute the picks, and pickers must roam around their designated areas looking for bots (see second illustration below). The only way to minimize this dual waiting effect is to add more bots, which creates two problems: higher costs, which tend to break the business case; and congestion, which reduces the productivity. In conclusion, we find that as compared to a high-density picking operation, the benefits of bots in cluster picking are low compared to their cost.

Read more: https://www.mmh.com/article/nextgen_supply_chain_bots_will_transform_your_distribution_operations