Logistics picking: optimizing with a WMS

Definition of picking in a "manual", semi-automated and 100% automated warehouse

Picking is the action of the "picker" who fetches ordered items, and assembles them for packing and dispatch. In a manual warehouse, these trips can add up to several kilometers a day... Picking is governed by two main principles: the "man-to-item" process, in which the order picker travels to fetch the products; and the "item-to-man" process, in which the item comes to the operator, thus limiting his travels, which can only take place in automated or semi-automated warehouses. This is a dynamic picking configuration, which changes according to logistical challenges, such as product seasonality, or the volume of items to be picked.

In the "man-to-item" process, several methods can be applied: the Pick and Pack method, which requires the picker following a printed list to pick items for one or more orders, and bring them to the packing area. The Put to Light method involves equipping operators with a display caddy, which indicates the location of the items, and where they are to be deposited. Finally, the Pick by Light method also uses lights and messages, which are displayed at the storage location where the items to be picked are located. This makes it easy to see where each item is to be picked. Each of these methods obviously requires a different type of equipment, with varying degrees of cost.

In semi-automated warehouses, for the "item-to-man" process, new technologies are continuously improving the operation of logistics warehouses. Picking can be carried out in two different ways: either robots bring the items to the packing area, or a central conveyor brings them there, as in industrial chains. Computerized processes, such as voice-activated order-picking systems, guide operators, and automated mechanisms help pack orders. However, this requires a number of parameters to be taken into account: starting with shelving, dynamic racks and shelving units, which need to be adapted to the chosen picking method; a precise labeling system to assist the operator with optimal product traceability; electronic terminals to locate the picking location and the place where orders can be deposited for packing; and finally, handling aid equipment, such as connected trucks, forklifts or pallet trucks.
Other large warehouses are 100% automated and computerized. In these cases, data alone determines the operators' picking path.

Different picking methods

Warehouse picking management is based on the supply chain, i.e. on the location of items and their purchase recurrence. A basic adaptation of the ABC storage method is very common, except for perishable products where the FIFO method (first in first out) must be applied, whatever the volume of shipment.
Finally, the weight of products must also be taken into account, with the heaviest items being picked first and placed at the bottom of the shelves, while the lightest are stored high up. In reality, there are as many picking methods as there are warehouse management options: from single-order picking (a single item picked and processed), to multi-order picking, in batches or waves, which enables several orders to be prepared within a given timeframe, for a given carrier or specific customers.

The advantages of a WMS in optimizing picking

In view of all the above parameters, it's clear that a WMS is an essential ally in the management of your warehouse. It enables you to calculate optimized picking times for your operators, which translates into immediate productivity gains. It also guarantees reliable order picking.

In conclusion, the WMS is a must for increasing the speed and reliability of order picking in the warehouse. Order-picking times will be reduced, inventory management optimized, and handling facilitated.