Order Picking Methods Include:
Discrete Order Picking - This is the most common type of order picking because it is basic and simple to understand. When employing a discrete order picking methodology, one order-picker picks one order, one line at a time. Additionally, there is only one order scheduling window during a shift. Therefore, orders are not scheduled and may be picked at any time on a particular day. The advantage of using this method of order picking is that it is simple, ideal for paper based picking, provides fast response time for order fulfillment and can easily track order picker accuracy. On the downside, this is the least efficient methodology as it requires a significant amount of travel time compared to other methods.
Zone Picking - As the name implies, order pickers are assigned a specific and physically defined zone in the pick area. The picker assigned to each zone is responsible for picking all of the SKUs that are located in the zone for each order. In the event that an order requires SKUs that are located in multiple zones, then the order is filled after it passes through each zone. This is typically referred to as "pick and pass" methodology. Additionally, in zone picking there is only one scheduling period per shift. Therefore, there is a cutoff point for orders to be queued into the order picking process and any order received after that cutoff point will get fulfilled during the next shift.
Batch Picking - Batch picking is when one picker picks a group, or batch, of orders at the same time, one SKU at a time. This is advantageous when there are multiple orders with the same SKU. When that occurs, the order picker only needs to travel to the pick location for that specific SKU once, in order to fill the multiple orders. Therefore, the main advantage to choosing this method is reduced travel time, which increases productivity. Batch picking is often used when the typical order profile has only a few SKUs (under four) and the SKUs physical dimensions are relatively small. Just as in zone picking, batch picking requires only one order scheduling window per picking shift.
Wave Picking - Wave picking is very similar to discrete picking in that one picker picks one order, one SKU at a time. The main difference is the scheduling window. In discrete picking, there is not a scheduling window whereas in wave picking there is. Therefore, orders may be scheduled to be picked at specific times of the day, which is usually done to coordinate and maximize the picking and shipping operations.
Zone-Batch Picking - This is a combination of methods in that pickers are assigned a zone, just like traditional zone picking, however they are also directed to batch pick within their zone. Since both zone picking and batch picking have a scheduling window, then zone-batch picking does too.
Zone-Wave Picking - This is a combination of methods in that pickers are assigned a zone and each picker within their zone picks all of the SKUs for all orders that are stocked in their zone, one order at a time with one scheduling window per shift.
Zone-Batch-Wave Picking - This is the most complex combination of all of the order picking methodologies. In this method, each picker is assigned a zone and picks all SKUs for orders stocked in the assigned zone. Additionally, the picker picks more than one SKU at a time and there are multiple scheduling windows per shift.