Enabling individual item picking in tomorrow's warehouses
Warehouses of today are facing increasing challenges in their picking operations. On one hand, they are required to support the growing e-Commerce sales where picking happens by unit (individual item or each picking). On the other, they continue to support existing store operations, where items have to be handled either in eaches or cases. Also, they are now forced to strike the right balance between the high-order-volumes-and-less-order-lines scenario of the e-comm world and less-order-volumes-and-high-order-lines scenario of stores.
In next 2-3 blogs, I will lay out the various picking methodologies and system capabilities and present the right combinations of methodologies and systems that warehouses must adapt.
A. Discrete Order Picking
Picker starts one order and completes entirely by visiting all the required locations. Picker will also operate any vehicle that might be required to pick specific item. This type of picking is used when orders are with low order volume distribution centers.
As one picker is fulfilling the order, order accuracy can be easily tracked back to the picker. On the downside, it may be inefficient method as picker has to travel entire warehouse to pick the order. This method becomes less viable when order volumes are more.
B. Pick & Pass Order Picking (Zone Picking)
In this process, pick locations are classified into different pick zones. Each picker is assigned specific zone and he/she is responsible to pick the items located in that zone. Once the picker is done with picking all items from the specific zone, (s)he passes it to the picker in the next zone.
This process allows the total travel distance to be minimized for pickers and they become more familiar with items located in their assigned zones. This familiarity can reduce pick time and can also balance the workload across pickers. Order accuracy can be tracked back to the picker as in discrete order picking. This process becomes more preferred when order volumes increase.
C. Batch Picking (Multiple Order Picking)
This process is used when there are common items across multiple orders. There are 2 methods in which batch picking can be achieved. In first, the item required for multiple orders batched together is picked and placed in a container. At the end of picking, required items are then sorted to respective orders.
In the second, different containers for multiple orders batched together are placed on a cart and item sorting takes place during picking. Picker immediately after picking sorts the item into the respective container.
Both processes are used where there are large volumes of each picking.
Batch picking improves productivity since the picker makes one trip to pick a number of orders.
It must be highlighted that all the above methodologies can be accomplished using paper picking. However, as the order complexity and order volumes increase, it becomes imperative to use advance picking systems like voice picking, RF picking, Pick-to-Light picking etc.
In the next blog, we will look into various picking systems and the relevant business scenarios that support them.
1 - Refer - Aberdeen Group Research article - Completing the Journey to Voice and the Paperless Warehouse, July 2012