Order picking bucket brigades are a way of organizing workers and orchestrating work in a warehouse pick module. The bucket brigade process balances workflow and distributes work evenly amongst the pickers, maximizing productivity and throughput. Top-performing bucket brigades typically use voice picking technology.
Pick Module Processes
Many DCs install high velocity pick modules for their fastest-moving products. In most pick modules, the products are packed densely in flow racks with a conveyor running in front of the shelves, so pickers can slide one or more totes or cartons along the conveyor as they pick items from the shelves.
In some pick modules the workers will pick all items in an order from beginning to end. When a worker completes his or her last pick, he will push the tote to the end of the module, and then walk back to the start to get his next order and a new tote.
In high volume operations, multiple pickers will work in each pick module, causing congestion as workers pick items from the same bays or pass each other working their way up and down the pick module.
An alternative to having each person pick complete orders is to place each worker in a defined zone spanning one or more bays in the pick module. Each worker will pick the items in his or her zone before passing the tote to the person working in the next zone. This eliminates congestion, but it leads to a different problem as some workers will inevitably be standing around at times waiting for work in their zone, while other workers are getting backed up in theirs. Zone-based picking is commonly used with pick-to-light technology.
Order picking bucket brigades solve the problems of congestion and uneven work distribution.
How Do Bucket Brigades Work?
In a bucket brigade, the person at the end of the pick module will complete the last pick in her order, push the tote off the line, and then walk up the line to where the previous worker is picking and take over that order. After the last worker steals the assignment, the previous worker will do the same to her predecessor, and so on. The effect is that every worker has work at all times, and no two workers are competing to pick items in the same bay at the same time.
Bucket brigades create a self-regulating flow of orders through the pick module, distributing pickers where there is work. To further boost productivity and throughput in the pick module, workers can pick multiple orders at a time in a so-called train of multiple totes or cartons.
Picking Rates With Bucket Brigades
Bucket brigades are used in a range of industries including bottle picking in wine and spirits and each picking for ecommerce or retail replenishment. Pick rates will vary depending on product density and velocity, order profiles, and a number of other factors.
Most DCs achieve picking rates of greater than 200 items per hour, with some surpassing 1000 lines per hour in the highest density operations. Voice technology typically delivers the highest possible picking rates in a bucket brigade, far higher than RF-based picking or pick-to-light.
Watch this brief animation to see how an order picking bucket brigade process can be used to optimize picking productivity and throughput in a traditional, manual pick module.
Batch Picking Bucket Brigades With Lucas
Lucas voice-directed bucket brigades offer an ability to batch orders in a train of cartons, so that the picker reaches into each slot once to fill multiple orders. The first Lucas batch bucket brigade system was installed as far back as 2004. These batch picking systems have led to ultra-efficient picking processes that just aren’t possible with lights or other technologies.
What are the Benefits?
Cost Savings from Increased Productivity
Compared to traditional single order bucket brigades, batch picking bucket brigades offer additional productivity gains resulting in significant additional cost savings. Best of all, these added points of productivity are essentially free – they are the product of creative process engineering rather than additional capital investments.
Lucas batch picking bucket brigades deliver improved accuracy as well. Pickers are required to explicitly confirm the quantity picked – they say “grab two” when picking two pieces. Voice-based bucket brigades also provide complete accountability since the system tracks who picks what into which order carton. To get the same level of accountability with a light-based system, associates would need to pick in fixed zones, which will inevitably lead to idle time and defeat the productivity goals of the bucket-brigade concept.