Picking Systems and Equipment

Key objectives in designing an order picking operation include

Piece Picking

Piece picking, also known as broken case picking or pick/pack operations, describes systems where individual items are picked.
Piece pick operations usually have a large SKU base in the thousands or tens of thousands of items, small quantities per pick, and short cycle times.
Mail order catalogue companies and repair parts distributors are good examples of piece pick operations.

Basic order picking.

The most basic order-picking method, inventory is stored in fixed locations on static shelving or pallet rack.
An order picker picks one order at a time following a route up and down each aisle until the entire order is picked.
The order picker will usually use some type of picking cart.
The design of the picking flow should be such that the order picker ends up fairly close to the original starting point.
The picking document should have the picks sorted in the same sequence as the picking flow.

Batch picking / Multi-order picking.

An order picker will pick all orders within the batch in one pass using a consolidated pick list.
Usually the picker will use a multi-tiered picking cart maintaining a separate tote or carton on the cart for each order.
Batch sizes usually run from 4 to 12 orders per batch depending on the average picks per order in that specific operation.
Batch picking systems may use extensive logic programmed to consolidate orders with the same items

Zone picking.

Zone picking is the order picking version of the assembly line.
In zone picking, the picking area is broken up into individual pick zones.
Order pickers are assigned a specific zone, and only pick items within that zone.
Orders are moved from one zone to the next as the picking from the previous zone is completed (also known as “pick-and-Pass”).
Usually, conveyor systems are used to move orders from zone to zone.
In zone picking it’s important to balance the number of picks from zone to zone to maintain a consistent flow.

Wave picking.

A variation on zone picking and batch picking where rather than orders moving from one zone to the next for picking, all zones are picked at the same time and the items are later sorted and consolidated into individual orders/shipments.
Wave picking is the quickest method (shortest cycle time) for picking multi item orders however the sorting and consolidation process can be tricky.