Everyone knows A items need to be close to the door and the floor for fast picking. But what happens when the season changes and the As become Cs? In many cases, nothing. Former A items do not get re-slotted, they get in the way and they slow down the picking process.
Fortunately, there are a number of common-sense practices companies can use to increase picking productivity. It starts with improving process efficiency, adding an incentive program or technology, and positioning products correctly in a pick-friendly format.
The first thing companies need to do is recognize picking is part of a larger process, says Don Benson, a 30-year industry veteran and independent consultant based in Portland, Ore. When a company starts to use a new picking system, he explains, managers need to first look at how well picking integrates with receiving and shipping, and try to optimize the entire process. Modifications may be needed to any of these areas to achieve the advantages the company expects from any new picking system. Companies also need to be aware of how well the entire process integrates into its supply chain.
Other questions to ask include: Does the process integrate into the culture of the business? Is the company prepared to deal with the higher degree of variability and the reduced manpower requirements of the new, more efficient process?
"The notion of integration having multiple dimensions is often overlooked," Benson emphasizes.
Great order picking is a team effort, says Robert Footlik, P.E., president of Footlik and Associates, Evanston, Ill. It starts in receiving where items are checked to make sure correct products are being positioned on shelves or racks in the ideal format—which includes place, location, size, sequence— that is conducive to picking.
A good shelf will have boxes that are open and labels that are showing. Loose items are stored in bins or other media that makes parts easily accessible. Boxes in pallet flow racks need to have the flaps torn off so they don't jam in the lanes. For pallet racks, stretch wrap on pallets needs to be peeled off and disposed of before the pallet is loaded onto the rack in a pickable position.
Timely and prompt stocking and replenishment is essential to an efficient picking process. If shelves are not fully stocked, pickers will stop their work to restock, which increases picking errors and reduces pick rates dramatically.
To ensure the shelves stay stocked, one approach is to implement a warehouse incentive program for everybody based on pickers' output. Even though pickers would get the lion's share of the payout, Footlik points out that this type of incentive plan radically changes paradigms in a DC because everyone realizes how they directly benefit from supporting the pickers. Some companies take the next step and conduct crosstraining so everyone has a shot at picking orders.
Back to basics
Some aspects of picking are so basic, that they frequently get overlooked, like slotting. Distributor operations sometimes make decisions about slotting that optimize receiving rather than picking. Making it easier to put away items rather than to pick and pack them, contributes to inefficiencies and increases the time it takes to pick orders.
Slotting software can help. However, the impact of software on the picking process is often overlooked. Managers do not realize that they need to change the requirements of the people who use of the technology. To effectively use the tool, these supervisors need to know how to maintain, coordinate and balance workloads.
Slotting software must be used regularly in order to keep SKUs current. Every SKU has a lifecycle, and they need to be moved or re-slotted on a regular basis.
"The advantages of slotting accrue when SKUs are regularly maintained; it is analogous to taking an annual inventory and cycle counting," Benson says. In the course of a week, DCs have heavy and light picking days. It makes sense to do cycle counting and reslotting on light days.
Picking decision rules that are built into the software can be used to slot complementary items together. Error-prone items need to be stored far apart when there is a tendency for pickers to misread two similar items. Hazardous items need to be in a hazardous room; temperature-controlled items need to be segregated; products with odors need to be stored away from things that absorb odor. Fragile items should go at the end of a pick path and heavy, dense ones at the beginning.
Many of these placements are a DC layout issue but, says Ken Ackerman (K.B. Ackerman Company, a Columbus-based consultant), "Layout and order picking are so closely entwined that the purpose of the layout is to facilitate the order picking."
The biggest technological gain for picking in the past 25 years is voice recognition, he says. Voice can be used for inventory and receiving, but the big bang is order picking. It lets workers work, hands-free, at their own pace. Voice technology reduces errors and increases productivity.
"It has a proven payback, as opposed to RFID, which gets a lot of ink and a lot of excitement, but has no payback for the warehouse operator," says Ackerman.
Some technology improvements that will improve picking efficiency can be as simple as properly programming the WMS so that items are listed in the same order the picker will find them in the warehouse.
"That is so logical you would think everybody does it," Ackerman says. "But everybody does not do it. I've seen order pickers who will mentally cherry-pick the order. They will pick item one, and read down the list and see that item eight on the list is near item one, so they pick item eight even though the paperwork does not allow them to do that. They have to do that in their heads, which slows them down."
Footlik says it is worth the investment in training and warehouse management systems to teach order pickers to pick and pack at the same time as they move along the pick path. In a pick/pack process, picked items are placed in a properly sized box in the right format for shipment. The box moves to an assisted carton finishing operation. A typical warehouse may have a ratio of two packers to one order picker. In a pick/pack system, the ratio is one order finisher to as many as 10 order pickers. The labor savings can be used to fund an incentive program. Any good WMS system can support pick/pack, he says.
