Warehouses are used to store all sorts of products. That can include massive equipment used by manufacturing plants; small items like nuts and bolts usually sold by hardware stores; clothes, generally sold by retail stores; and more. The product sold is going to influence the way a warehouse is operated and what methods are used to pick the products for shipping.
There are three methods of picking; each designed to handle particular types of products in the most efficient manner. This includes piece picking, case picking, and pallet picking.
Piece picking is perhaps the most basic. Also referred to as broken case picking or pick/pack operation, the procedure is designed to handle a massive amount of SKUs and calls for a worker to
pick individual items within a short time cycle.
There are four categories of piece picking:
· Basic order picking. In this case, products are stored in set locations on stationary shelves or pallet stands. A laborer picks one order at a time as he walks up and down aisles toting a cart in which he can store the items he picks. Fast-selling products are stored on the lower shelves close to cross aisles to assure easy accessibility. Bulkier products are stored at the end of the pick flow. This design could prove ideal for an operation that handles a small number of orders and a moderate to high number of picks per order.
· Batch picking/multi-order picking. In this category, multiple orders are gathered together into small batches and the order picker refers to a consolidated pick list as he picks all orders within a batch in one pass. The picker totes a multi-level cart, which includes a carton for each order. A batch equals from 4 to 12 orders. Batch picking permits the picker to cut the amount of
time it takes to gather multiple orders by making picks in the same area. This method works efficiently only if orders are collected within the system until there are enough comparable picks to create batches. Keep in mind that this delay in the process may not be appropriate when performing a same day shipping operation. Batch picking will work well when total orders are low to high and picks per order are low.
· Zone picking. This style of picking has been compared to an assembly line. In this case, the picking area is divided into individual zones and pickers are assigned to a specific zone. As picking is completed in one zone, the process moves on to the next zone. Commonly, conveyor belts are used to pass an order from one zone to another. So it is imperative that zones are created near conveyor belts. Each zone is sized to accommodate no more than two pickers. Zone picking permits specialization of picking techniques within each zone. For example, automated material handling can be used in one zone and manual picking can be performed in another zone. Zone picking will work well in situations where there are moderate to high total orders and low to moderate picks per order
· Wave picking. In this form of piece picking all zones are picked at the same time, then orders are sorted later and consolidated into individual shipments. Wave picking can be performed faster than any of the other piece picking methods. However, the procedure of sorting and consolidation can be a little difficult to master. Wave picking may prove ideal for an operation that has low to high total picks and moderate to high picks per order.
Equipment needed for piece picking include:
· Stationary shelving
· Carton flow racks
· Carousels
· Automatic storage and retrieval systems (ASRS)
· Automatic picking machines
· Pick-to-light
· Bar-code scanners
· Voice-directed picking
· Automated conveyor and sortation systems