Wave picking, also known as cluster picking, is one of several warehouse order picking systems to improve efficiency. It involves releasing specific orders to the floor for fulfillment, based on a common factor such as shipping date, items, warehouse zone, etc. Rather than scheduling a number of pickers per shift and then hoping that orders flow accordingly, wave picking helps teams to meet specific commitments, such as filling a set number of orders per shift or meeting a shipping deadline.
To do so, wave picking focuses on when orders are picked. Management aligns short picking intervals, or waves, with other warehouse variables, such as the transportation plan or departure schedule. The result is that orders are grouped and then picked, but only at certain times of the day. Teams gain efficiency primarily by reducing (or eliminating) picker idle time. In other words, a wave might not be scheduled until all orders up to a specific deadline have come in, so pickers don’t have to spend time waiting for instruction.
How Does Wave Picking Work?
Although the concept is straightforward, executing wave picking can be complicated because it requires a collaborative effort between multiple roles involved in the order fulfillment process, including receiving, shipping, freight companies, and others. Because of this, wave picking is most effective when seen as a three-step process:
- Pre-wave picking is the work of scheduling the waves according to specific variables. As a business processes orders, they must be logically grouped and scheduled. If they’re grouped by shipping time, for example, picking must have enough lead time to pick the orders and get them packed before the shipping partner’s scheduled departure time. This planning is much easier with the help of a warehouse management system (WMS) that can factor in all necessary variables to create an optimal picking schedule; done manually, it’s laborious and time-consuming.
2. Performing wave picking is the act of picking. It’s made more efficient with technology like hand-held mobile scanners that provide digital pick lists and direct pickers to product locations, instead of paper pick slips. These technologies can be linked to a WMS and chart optimal pick routes while tracking each step of the picking process. Using a hand-held picking device, wave picking typically works like this:
*A picker receives the pick list for 4-12 orders per wave.
*The picker uses a multi-tote cart to keep the orders separately.
*Pickers are sent to each storage location in sequence, and the mobile device tells the picker the SKU and quantity to pick. Pickers pull the designated product and scan its barcode to confirm the pick.
*Pickers place the product in its appropriate tote and scan the tote’s barcode to confirm. Pickers might also enter the quantity on the mobile device.
*Pickers are then directed to the next pick and the process repeats until all orders are complete.
3. Post-wave picking occurs after the items are picked. Often, orders are kept separate as they’re picked; mobile scanners and discrete totes or cartons can make this easy. But if orders are not separated, the product must be organized for sorting and packed for shipping afterward. Scheduling waves must allow time for the added sorting and packing step if necessary. Finally, orders are loaded and shipped.