An In-Depth Guide to Warehouse Picking Methods

Order picking is a vital part of warehouse operations, directly impacting the efficiency of your operations and the accuracy of order fulfillment. With several order picking methods available, it's essential to understand the differences between them and their unique benefits. Let’s dive into seven popular order picking methods – what they are, and the benefits of each – to help you choose the best strategy for your warehouse.

Discrete/Single Order Picking


Discrete order picking, also known as single order picking, involves picking items for one order at a time. A picker retrieves all the items required for a specific order before moving on to the next order.


Benefits of Discrete/Single Order Picking:

  • Simplicity: This method is easy to understand and implement, making it suitable for smaller warehouses or those with lower order volumes.
  • Focused: Because pickers pick one order at a time, there's a reduced risk of mixing items from different orders.

Batch Picking


Batch picking involves picking multiple orders simultaneously by grouping them into batches. Orders are most commonly grouped into batches based on SKU commonality. Combining like orders into a batch for concurrent fulfillment will speed the fulfillment process as the worker only has to visit the item location once to fill multiple orders. Pickers retrieve all the items needed for the orders within the batch and fill them simultaneously. 

Benefits of Batch Picking:
  • Increased efficiency: Batch picking allows for faster processing of orders, as multiple orders are picked at once, reducing the overall picking time per order. This can result in higher productivity and throughput, particularly for larger volumes of orders.
  • Reduced travel time: Batch picking can reduce the total travel time required to pick items, as multiple orders can be picked from the same area of the warehouse, reducing the distance traveled by pickers.
  • Optimized use of resources: Batch picking can optimize the use of resources, such as labor, as fewer pickers may be required to pick the same number of items as would be needed for discrete order picking.
  • Lower costs: By optimizing resources and reducing travel time, batch picking can help reduce overall operational costs, particularly for larger order volumes.

For a Deeper Dive on Batch Picking: How to Implement Batch Picking in Your Warehouse




Cluster Picking


Cluster picking is similar to batch picking – the difference is in the way the orders are grouped together into the cluster for fulfillment. In cluster picking, orders are grouped based on similarity such as order size or shipping method. As with batch picking, pickers then retrieve items for all the orders in their cluster and route them to shipping.


Benefits of Cluster Picking:
  • Increased efficiency: Cluster picking allows for multiple orders to be picked at once, reducing the number of trips required to pick items, increasing overall efficiency.
  • Reduced travel time: Cluster picking reduces travel time and can minimize the need for backtracking or reorganizing inventory within storage locations.
  • Optimized use of resources: Cluster picking can simplify order processing, as it can help consolidate multiple orders into one pick ticket or work order, reducing paperwork, administrative tasks for better use of resources.
  • Lower costs: Cluster picking can reduce labor costs as it requires fewer personnel to fulfill multiple orders at once, lowering the overall costs in the warehouse.



Cross Picking


Cross picking allows a worker to pick from one zone and put into two zones. To accomplish this, two pick zones are positioned facing each other with the batch station in the middle. The batch station is equipped with a side-by-side roller conveyor with a series of alternately angled flow racks (also called slides) on top. Order totes sit on top of the conveyor and below the slides allowing items from each zone to be put into the order tote as required.


Benefits of Cross Picking:

  • Time savings: The simultaneous picking from multiple zones reduces overall picking time.
  • Labor optimization: By doubling the workload among multiple pickers, cross picking can enhance productivity dramatically in most organizations.

For a Deeper Dive on Cross Picking: What is Cross Picking in a Warehouse?


Pick and Pass


Pick and pass is a picking method where workers “pick” all required items from one zone and then “pass” the order to the next zone for additional items. Zones can be created by any criteria that makes sense to your operations such as SKU velocity, SKU size, storage method, etc. If no items are needed from a zone, the order skips to the next zone. Once all items for the order are retrieved the order is routed directly to shipping.


Benefits of Pick and Pass:

  • Customized order routes: Orders only travel to zones containing the required items, streamlining the picking process and filling orders quickly.
  • Increased flexibility: This method can be easily adapted to handle fluctuations in order volume or product mix.
  • No consolidation needed: as order totes pass through zones collecting the items for the oder along the way, no consolidation step is needed.




Zone Picking/Parallel Picking


Using a zone picking method, also known as parallel picking method, each worker is still assigned a zone; but all zones are picking the same orders in parallel. Instead of the worker passing the partial order throughout the warehouse for fulfillment, the partial order is sent to a consolidation area. Partial orders wait in the consolidation system for the arrival of the rest of the parts needed for that order. Once all parts required arrive at consolidation, the parts are combined together to create the complete order and then sent to shipping.


Benefits of Zone Picking/Parallel Picking:

  • Expertise: Assigning pickers to specific zones allows them to develop familiarity with the items and equipment in their area, increasing picking speed and accuracy.
  • Reduced travel time: Pickers stay within their designated zones, minimizing unnecessary movement.
  • Order verification: orders can be double checked for accuracy in the order consolidation step for increased order accuracy.

Wave Picking


Wave picking combines elements of discrete and batch picking. Pickers retrieve items for multiple orders simultaneously, but the picking process is organized into waves, typically based on factors such as order priority, shipping deadlines, or item locations. Wave picking is a common order method for larger e-commerce order fulfillment operations.


Benefits of Wave Picking:

  • Better scheduling: Organizing picks into waves enables more effective prioritization of orders and resources.
  • Improved productivity: Combining the advantages of both discrete and batch picking, wave picking allows for a more efficient picking process.


For a Deeper Dive on Wave Picking: Wave Picking in Warehouses


By understanding the nuances of discrete order picking, batch picking, cluster picking, cross picking, zone picking, pick and pass and wave picking you can determine which method aligns best with your warehouse's unique requirements. Consider your warehouse size, order volume, and product mix when choosing a picking strategy. Ultimately, a combination of several picking methods is usually the best solution. 


For a Complete Guide to Order Fulfillment: Strategies to Improve Your Order Fulfillment Process