Planning for Waves
You should set up your wave or waves at the beginning of the day to reflect the order lines your company typically completes for a particular time period, such as a single day or a couple of days. Wave planning creates the picking and replenishment tasks for the wave. Use Wave Open Order Report (4.15.13) at the start of a work day to globally view the workload for the current day, next few days, and so on.
Before creating the wave, you should consider which orders to pick for the wave and how many orders to include on the wave. If your company typically completes about 7000 order lines in a day, you can set the maximum for each wave to be 1000 order lines. This means setting up seven waves at 1000 order lines for a single day or setting up 70 waves at 100 order lines for a day, and so on.
You can set defaults for the maximum order lines in a wave and this helps control the wave size. If you have too many waves, they are difficult to monitor. If you have too few, you loose flexibility.
The main objective of wave planning is to have continuous throughput for picking and shipping operations. Plan the wave based on workload, staff, and carrier type; then monitor the workload based on aisles, congested areas, and carrier arrival.
To do this, consider the workload in the different aisles (workgroups) to determine the size of the wave. You must also consider the capacity of the shipment area before you release orders. If you release too many orders at the same time, you may block aisles with staff and their carts. Next, consider the number of orders for each carrier type and know the arrival time and location for each carrier type.
Further, a method to manage the location of staff and the movement of carts or forklifts is required to move the items with maximum efficiency. For example, if you have 30 staff picking in 18 different aisles, you may want only two or three staff picking in a single aisle at any given time. Moreover, if your warehouse uses wire-guided forklifts, you may want only a single forklift in an aisle at any given time.
While monitoring, you can optionally move, add, or delete order lines. Although you can have multiple order lines from multiple orders on a single wave, you cannot have the same order line on two different waves. The system allocates only one order line from a single order per wave. Certain criteria must be met before you move or delete an order line from a wave.
Wave Sizes
It is difficult to recommend how many order lines you should have on a wave to constitute a typical wave size. The number of lines, and hence, the size of the wave, depends on the industry, items, order volume, and the number of shipments.
Typically, you can reasonably manage 10-15 waves per day. This allows enough visibility for the person controlling the waves to ensure that waves are processed and closed.
Take the following into consideration when determining the size of your waves:
1 The more waves you have in the system, the less wave visibility.
One or more users should act as wave planners who manage warehouse staff workflow and capacity, replenish waves on time, and release waves so that the system assigns tasks to warehouse staff. Too many waves can complicate and confuse both planners and staff.
The wave planner’s objective is to start, replenish, release, and complete a wave with some overlapping when the next wave is started. To this end, there may be several waves at the same time, but not so many as to increase the amount of time needed to complete the waves.
2 Processing only a few big waves in a day impacts the space required in the picking locations.
For a single large wave, the required quantity in the picking location increases. It may not be possible to increase the picking locations in your warehouse. If your warehouse has on overflow area that you can use, this may not provide the best result. Wave planners lose visibility in overflow areas. Because overflow areas are typically floor locations near aisles, wave picking becomes more cumbersome, complicated, and dangerous for warehouse staff who may have to avoid pallets in walkways.
3 Consider the carriers, truck loads, and so on, departing from your warehouse each day.
Wave planners should consider step 1 and step 2 before determining the number of waves per carrier, truck load, route, and so on. After examining the first two steps above, wave planners may decide, for example, that it is better to have one wave for two truck loads or two waves per one truck load.