This blog continues the series ‘Take a Walk with Me’, which invites you to virtually walk through each functional area of the warehouse with a focus on identifying improvements.  These improvements might include reducing travel distances, decreasing material handling labor, improving accuracy, increasing storage capacity, adding locations, and enhancing safety.  Despite differences in people, products, and systems, most facilities share core functions: receiving, stocking, storage, inventory management, order picking, packing, and shipping.

The previous two blogs in this series discussed Receiving and Stocking, and now we move onto Order Picking. This is arguably the most important process in the distribution center.  Based on various distribution studies, Order Picking accounts for up to 50% of the total labor cost.  Replenishment accounts for up to 25% of the total labor cost, but that will be the topic of our next discussion.

It is no surprise that based on the 2025 WERC DC Measures report the top 10 metrics include multiple measures for the order picking function: picking accuracy-#3, internal order cycle time-#7, total order cycle time- #8 and lines picked per person hour-#9.

Strategies

Order picking can be accomplished from the storage area or within a separate forward pick area.  The design may be hybrid, with slower items picked from storage and faster items set up in a forward pick area.  The best approach depends on the size of your facility, number of items, volumes, and order profiles.  In general, larger, high-volume operations with thousands of items tend to have forward pick areas, while smaller, lower volume operations with less items tend to pick from the storage area.

In more manually focused operations, you are either going to walk through the storage area, where picking is likely set-up in floor level positions, or walk through a forward pick area setup with mezzanines or multi-level platforms and separate pick media equipment.  Within the storage area, floor level pick locations are replenished with reserve storage within proximity to the pick locations. And, with a forward pick area, the reserve storage area is accessed to retrieve and deliver replenishment.

Methods

Regardless of the set-up, the methods employed for the picking process are a great place to start observations.  The various best practices for the picking process include:

• Discrete Picking (Single Order Picking): A picker handles one order from start to finish. It is very simple and provides the highest accuracy levels but can be inefficient for small orders and large warehouses.
• Cluster Picking: A picker gathers items for multiple orders at the same time, placing them into separate bins/containers for each order during a single trip. This is very common with single line order processing.
• Batch Picking: A picker grabs the same item for several different orders in one trip, which is efficient for products ordered frequently.
• Wave Picking: Orders are grouped into “waves” based on factors like order type, deadlines or carrier pick-up times to improve efficiency and coordination.
• Zone Picking: The warehouse is divided into zones, and each worker is assigned to a specific zone to pick items. Orders are consolidated on the dock.
• Pick-and-Pass: An extension of zone picking where the order container is physically passed from one zone to the next after items are picked in the first zone through completion.

Pick Media

As you walk through the pick area, look for empty locations, products sitting on the floor, and/or labor congestion.  The selection of the pick storage equipment / media is critical to the balance of pick and replenishment labor.  Under size the pick location and you may stock out during picking, incur higher replenishment labor and introduce congestion in the pick area.  Oversize the pick location and you risk enlarging the pick area and increasing the travel distance.  The ideal strategy is to do detailed data analysis and establish the targeted days of supply in the pick location to minimum replenishment and not oversize the pick area.  Consider the following examples as you observe your equipment and related activity:

• Bins on Shelving: tiny items, slow to fast movers (example – 1 ft deep x 0.5 ft wide x 0.5 ft tall)
• Shelving: small items, slow to med movers (example – 1.5 ft deep x 1.5 ft wide x 1.5 ft tall)
• Decked Rack Shelving: med movers/med size (example – 3.5 ft deep x 2 ft wide x 2 ft tall)
• Carton Flow Rack: med-fast movers/med size (example – 8 ft deep x 2 ft wide x 2 ft tall)
• Pallet Rack: med-fast movers/larger (example – 4 ft deep x 4 ft wide x 6 ft tall)
• 2 Deep Pallet Flow Rack: fast movers/larger (example – 8 ft deep x 4 ft wide x 6 ft tall)
• Deeper lane pallet flow options – very fast movers, medium/larger size items

Material Handling & Technology

As you walk through the pick area, consider how much labor is required handling products and equipment and the amount of congestion in the aisles. Depending on your order pick volumes and profiles, the following are possible material handling considerations:

• Push carts – various size, configuration and weight for each picking
• Smart carts – integrating RF/lights on cart for each picking
• Pallet riders – carry pallet behind picker for case picking
• Pallet riders, longer forks – carry two to three pallets through the pick path
• Multi-level pallet riders – enabling pick from higher pick levels (i.e. ~ eight (8) feet)
• Tugger Rider – pull train of shelf carts to pick orders for each/case picking
• Multi-level pick platforms – integrating conveyor, zone-route diverts, and a sorter.
• Shuttle technology – many variations from linear through roaming shuttles.
• AutoStore – top level shuttle technology.
• AMRs – many variations including carrying shelves, totes, and pallet loads.

Technology can enhance conventional designs with a lower investment than larger automated systems.

• Pick to light – free hands and add lights to pick locations to direct pickers
• Pick to voice – free hands and direct pickers with voice commands
• Put walls – integrate with batch picking, follow lights to place orders into wall cubby’s

Closing

With so many variations in order types, sizes and profiles, and technology options it is difficult / risky to share order pick metric guidelines.  But, based on the 2025 WERC DC Measures report the best-in-class results for the top order picking metrics are as follows:

• Picking accuracy-#3: >= 99.68%
• Internal order cycle time-#7: < 3.36 Hours
• Total order cycle time- #8: < 6 Hours
• Lines picked per person hour-#9: >= 70 per Hour

And here are some project labor rate examples using various picking applications.

• Pick pieces manually shelving using pick cart – 100 lines/hour
• Pick pieces into tote using module zone divert systems – 300 lines/hour
• Pick pieces from shuttle system – 600 lines/hour
• Case pick from pallet rack using pallet rider – 150 cases/hour
• Case pick to conveyor belt – 350 cases/hour

Take a walk through your order picking process and identify potential areas of improvement leveraging the information shared in this blog.  Validate and/or document standard operating processes, review WMS capabilities, estimate current labor standards, and collect data to evaluate identified improvements.  Determine the impact of the identified improvements and any related capital costs.  Then, build the business case for change. If you need support with any of these tasks, please consider St Onge Company.
 
—Norm Saenz, St. Onge Company
 
 

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