Order picking can be defined as the activity by which a small number of goods are extracted from a warehousing system, to satisfy a number of independent customer orders. Picking processes have become an important part of the supply chain process. It is seen as the most labor-intensive and costly activity for almost every warehouse, where the cost of order picking is estimated to be as much as 55% of the total warehouse operating expense. As the order picking process involves significant cost and can affect customer satisfaction levels, there have been increasing numbers of process improvements proposed to help companies with this supply chain issue.
Solutions For Order Picking
A number of supply chain academics such as G.P. Sharp and Edward Frazelle have proposed a number of ways of classifying the order picking system. Four solutions have been identified for order picking.
- Picker to Part
- Part to Picker
- Sorting System
- Pick to Box
Picker To Part
This particular method is very common and found in most warehouse environments. The process involves a storage area, a picking area and a material handing system that is used to refill the picking locations from the storage area, which can be forklift based or more specialized such as gravity flow racks. The storage area will contain the items required to fulfill the customer orders. The picking operator can then pick the items for each customer order from the items stored in the picking area. As all the items are in a smaller area than the regular warehouse, the picking operator can fulfill the order more efficiently than if they had to pick the items from the general storage area in the warehouse. The gravity flow racks are especially useful for items that are commonly ordered so the picking operator can be in one location and pick items from the trays in front of them. There are a number of technological advances in “picker to part” processes such as “pick to light” or “voice picking”. These systems allow picking operators are informed which item to pick based on a light appearing on the item location or a voice informing the operator on a headset which item to pick.
Part To Picker
The part to picker method employs the same physical locations as the previous method; storage area, picking area and a material handling system that moves the items from the storage area to the picking area. The difference with this method is that the picking area is made up of a series of picking bays. The items are moved from the storage area and delivered to the picking bays. Each bay receives the items for one or more orders. The picking operator collects the items delivered to their bay and the customer order is fulfilled in this manner. This method can be subject to wasted labor as picking operators can find themselves waiting for items to be delivered to their picking location.
The sorting process including the requirement for a picking area, a storage area, replenishment of the picking area and a sorter. This method uses automatic material handling system consisting of multiple conveyors and a number of sorting devices. The items are placed on a conveyor in the storage area and the items are sorted for each particular order. The operator in the picking area collects the items that have been sorted for a customer order and processes that order. The efficiency is gained because the operator does not have to consume time collecting individual items.
Pick To Box
Pick to box is similar to the sorting solution as it uses the same elements; a picking area, a storage area, replenishment of the picking area and a sorter. The picking area is organized so that there are a number of picking zones connected by a conveyor system. The operator fills the box with the items on a customer order and the box moves to the picking zones until the customer order is complete and it is then ready for shipment to the customer. The efficiencies are gained because the operator does not have to consume time collecting individual items, but the cost of the initial set up of this solution could negate any cost benefits that the solution offers.
Choosing an order picking system depends on any number of requirements such as cost, complexity, number of customer orders, size and number of items, etc. Every company has a unique requirement and one order picking solution may suit one business and not another. Determining the requirements will ensure that the most efficient order picking solution is selected.