Sorting Goods

Sorting is typically done using a sorting wall — a special cart or rack where each individual bin is reserved for a specific order. That is, a warehouse worker takes an item from the picked batch, scans it, and the WMS tells them: “Place this item in bin number 31.”

By scanning each item in the wave, the system transforms N items into M distinct orders. Each bin will then contain the full contents of a single, specific order, making them ready for packing with no confusion.

There are two main types of goods sorting:

1. Sorting during picking using a sorting trolley

   
   

   In this case, the worker brings a small sorting wall (trolley) with them. After picking an item from the shelf, they scan it, and the WMS immediately tells them which bin to place the item into.

   

   
   

   Pros: the picking and sorting processes are combined, which saves warehouse space (no need for a dedicated sorting area) and increases speed (one scan handles two processes). The sorted goods go directly from the picker to the packer.

   Cons:

   1. Only suitable for small-sized goods.
   2. The worker has to move around with a fairly large and often heavy structure.
   3. The number of orders in a single wave is strictly limited by the number of bins in the sorting trolley.
   4. Only one worker can handle picking for a single wave.

2. Sorting as a separate process using a sorting wall

   
   

   In this case, all pickers bring the collected goods to a designated sorting area — a large shelving unit with bins sized to fit individual orders. A separate employee then performs the sorting process.

   

   
   

   Pros:

   1. The wave size (number of orders it includes) can be significantly larger.
   2. Multiple employees can work on picking a single wave simultaneously (e.g., each one responsible for their own aisle). This significantly speeds up the process!
   3. This introduces an additional layer of verification — allowing time to resolve any issues without blocking the workflow.
   4. Strategically placing the sorting wall can physically separate long-term storage from the processing zone, which benefits process clarity and product safety.
   5. It provides substantial buffering of goods — but more on that in the next section.

   Cons:

   1. It introduces another process, which means more staff and additional time spent on sorting. And time = money.
   2. Requires a dedicated area in the warehouse. In some cases, space can be a critical issue.