Designing Picking Routes in E-Commerce Warehousing

In warehouse operations, there is no “perfect” picking method or route—only the one that fits your layout and order structure best. The design of picking routes and methods depends heavily on shelving layout, product placement, and clear labeling.

 The 4 "S-Shaped" Principles of Picking Design

Picking efficiency is optimized using four nested S-shapes:

1. S-Shaped Shelving Layout

2. S-Shaped Picking Routes

3. S-Shaped SKU Numbering

4. S-Shaped Eye Movement Pattern

These S-shapes are interrelated:

· The S-shaped layout of shelves determines the S-shaped path that pickers follow.

· The S-shaped SKU labeling on multi-level shelves guides the S-shaped visual search path.

This design ensures pickers walk the most efficient route—starting and ending at the same point, with no redundant backtracking. In warehouses where both the entry and exit are on the same side, this route minimizes physical effort.

Example: Aisles are arranged with odd numbers on the left and even numbers on the right, guiding pickers in an S-shaped walk pattern.

Each shelving unit has multiple levels, and SKU numbers are arranged top-to-bottom in an S-shaped flow, which also enhances search efficiency.

Picking Methods: By Order vs. Batch Picking

Once the route is set, picking method must be selected. There are two main strategies:

1. Order-Based Picking

Each order is picked individually, with items placed into separate baskets or containers during the walk. Baskets go directly to the packing station.

Pros:

· Easier for packers (no need to sort)

· Saves time in final order processing

Cons:

· More trips for pickers

· Longer time per picking task

2. Batch Picking (Wave Picking)

Items from multiple orders are picked in bulk without sorting. They are then sorted and packed at the packing station by packers.

Pros:

· Reduces walking time for pickers

· Efficient for high order volumes

Cons:

· Shifts workload to packing staff

· Requires extra sorting at the packing stage

 Hybrid Picking for Large Warehouses

In large-scale warehouses or during peak periods, a hybrid picking strategy can be used:

· Pickers gather multiple orders in one trip (batch picking)

· A second team member sorts items by order during the picking process, placing them into separate containers

This approach combines the speed of batch picking with the organizational advantages of order-based picking—but requires two workers per picking task.

Recommendations by Order Volume

Final Thoughts

Optimizing your picking route and method is crucial for boosting efficiency and reducing labor costs in e-commerce warehousing. By leveraging the 4S design principle and choosing the most suitable picking strategy, your warehouse can achieve faster order fulfillment, better space utilization, and higher customer satisfaction.