12 Different Types of Warehouse Order Picking Methods

Allison Champion
6 min read
January 23, 2019
Modified: October 10, 2023

When order fulfillment operations are considered as a whole, it’s easy to see why shipping and warehousing receive most of the technical praise. The e-commerce industry relies heavily on how the order picking methods are done when their inventory is being fulfilled.

Shipping is the face of every e-commerce delivery, and fulfillment warehouses are incredibly advanced structures capable of housing an astonishing amount of inventory.

Behind the scenes of e-commerce fulfillment is a series of sophisticated operations and warehousing KPIs that ensure the successful delivery of online purchases, and therefore the continued business of online customers.

What Is Order Picking?

Few, if any, consumers consider the complicated operations that ensure the successful delivery of an e-commerce package to their doorstep. Most are simply happy to receive their online purchase on time and in one piece.

However, the backbone of every successful online shopping experience is not shipping, warehousing, or even the internet, but order picking strategy, an integral part of the pick, pack, and ship process, which accounts for more than 50% of all fulfillment center operations.

Warehouse order picking refers to the process of removing items from the inventory in order to fill a customer order.

Pallet and case picking for orders is a fulfillment center’s most complicated, labor-intensive, and essential operation; therefore, it’s also its most expensive.

Types of Order Picking Methods

Consequently, fulfillment centers and third-party logistic (3PL) providers who conduct their picking process and order fulfillments with the utmost speed and accuracy are, unsurprisingly, the most successful.

There are several different types of order picking methods, all of which are engineered to increase the speed, accuracy, and overall efficiency of the warehouse operation.

Single Order Picking

Single Order Picking refers to the picking process wherein an order picker journeys into a vast warehouse to pick order items from inventory to fill an individual order at a time. Single order picking is also referred to as discrete picking and piece picking.

Though the single order picking process is the most commonly employed picking method, it is not the most efficient. In most cases, the sequence in which a picker is likely to find, pick, and fill SKU items is not optimized to increase speed or accuracy, thus wasting time and money.

Warehouse Management Systems (WMS) provide the exact location of SKU items in a warehouse and optimizes a pickers route to retrieve it from the pallets the inventory sit on.

Wave picking utilizes a similar method in which one order picker will go after an individual SKU at a time, however the orders are grouped into waves to match shipping and schedule times.

Batch & Multi-Batch Order Picking

Fulfillment centers who employ Batch and Multiple Order picking methods enjoy a step up on those who employ a single cased picking method.

Order pickers utilizing a batch order picking method utilize warehouse management systems to pick SKU’s from the warehouse to fill more than one order at a time, thus eliminating unnecessary trips to the same storage area of the warehouse.

Batch picking methods are, in most cases, compatible with automated shipping systems.

Cluster Picking

Cluster picking is a technique where a picker is tasked with fulfilling several orders simultaneously. As they navigate the warehouse, they have multiple bins or containers with them, each corresponding to a distinct order. As items are retrieved, they’re placed into their respective bins. This warehouse order picking method shines particularly when there are common items across multiple orders, eliminating the need for repeated trips to the same location.

Zone Picking & Passing

Different SKU items have different storage requirements; thus most warehouses are divided into specific zones that are specially equipped to house different SKU items.

Warehouses that utilize the zone picking method typically “pick and pass” SKU items from zone-to-zone to be packaged and shipped from a central order consolidation location.

However, it’s not uncommon for different zones to function independently of other zones in the warehouse layout .

A refrigerated warehouse storing meltable inventory, for example, may include a “frozen” zone that consolidates and ships frozen orders independently of the “dry” and “reefer” zones to maintain the integrity of frozen SKU items.

Advanced Zone Picking Techniques

Zone-Batch Picking

Combining the principles of zone and batch picking, the zone-batch picking method assigns pickers to specific zones. However, instead of picking for a single order, they pick items in batches. This means they retrieve items for multiple orders during a single trip within their zone.

Zone-Wave Picking

In zone-wave picking, pickers are assigned zones and pick items for all orders within their zone, one order at a time. The difference here is the introduction of scheduling windows or “waves” that group orders based on certain criteria, optimizing the picking process.

Zone-Batch-Wave Picking

The most intricate of the zone picking methods, zone-batch-wave picking combines, you guessed it, zone, batch, and wave picking! Pickers are assigned zones and pick items in batches during specific scheduling windows. It’s a comprehensive approach that maximizes efficiency but requires sophisticated warehouse management systems to implement effectively.

Autonomous Order Systems

Automation technology and the growing role of AI in supply chain management has significantly affected how fulfillment centers pick and fill SKU items. In fact, a growing number of fulfillment centers have become fully, or partially autonomous.

Autonomous Order Systems generally include a sophisticated array of tracks and automated pickers who utilize artificial intelligence to find and retrieve specific totes from inventory and deliver them to designated consolidation areas. Thanks to technology, the automated order picking function saves the warehouse manager time and money.

Within the consolidation area, an employee or another automated system selects the requested SKU item and positions the tote on a track to be returned to its designated position within the warehouse. Let’s take a closer look at some types of automated warehouse order picking systems

Pick-to-light Systems

Pick-to-light systems are an automated method where LED lights guide pickers to the correct items and quantities. Once an order is activated, lights illuminate on the storage bins or shelves, indicating where items need to be picked from. It’s a visual system that speeds up the warehouse picking process and reduces errors.

Voice Picking

Voice picking is where pickers wear headsets that provide verbal instructions on which items to pick and their locations. After retrieving an item, pickers verbally confirm, ensuring a hands-free and efficient process.

Mobile Scanner-based Picking

All items in the warehouse have unique barcodes. Pickers use mobile scanners that display the pick list and item locations. As items are picked, they’re scanned, ensuring accuracy and real-time inventory updates.

Collaborative Mobile Robots

The future of order picking! These robots assist human operators, handling the manual task of moving products. They can be programmed to follow various warehouse picking methods, optimizing routes in real-time using artificial intelligence.

Incorporating these advanced order picking methods can significantly enhance the efficiency, speed, and accuracy of warehouse operations. As the e-commerce industry continues to grow, adopting these techniques can give businesses a competitive edge, ensuring customers receive their orders promptly and accurately.

Final Thoughts

Fulfillment centers are incredibly sophisticated operations that support the astoundingly vast e-commerce industry, but without an equally sophisticated picking system, even the most well-funded fulfillment center is bound to fail.

The best way to ensure your order fulfillment operations are optimized for speed, accuracy, efficiency, and success is to trust them to the supply chain, logistics, warehouse and fulfillment experts here at Flowspace. Click below to make sure you receive the best customer satisfaction from your customers!


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Written By:

flowspace author Allison Champion

Allison Champion

Allison Champion leads marketing communication at Flowspace, where she works to develop content that addresses the unique challenges facing modern brands in omnichannel eCommerce. She has more than a decade of experience in content development and marketing.

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