Ways to find warehouse space
By Clair David Urbain

Warehouse space: There never seems to be enough of it in busy facilities. But there are ways to find space in your present facility, and warehouse management consultants Gross and Associates have assembled many great ideas in their book, How to Save Warehouse Space: 152 Tested Techniques. It is written by Jack Kuchta and others at Gross and Associates.

Below, a few of the many ideas are featured; to get a copy of the book, contact Distribution Center Management, 215 Park Avenue South, Suite 1301, New York, NY 10003-1603 or call 212-228-0246. The book can also be ordered online at www.grossassociates.com.

Design ideas

Limit wide picking aisles. In warehouses with narrow or very narrow aisle storage equipment, some aisles may be intentionally widened to allow pickers to pass one another.

The wider aisles increase output by avoiding waiting by pickers, but they sacrifice storage space. To control aisle congestion. a warehouse management system can control picker activity through RF or infrared onboard terminals by making dynamic work assignments that limit the number of pickers in an aisle.

Use a battery changing area rather than charging stations. When you must charge batteries during work hours, a changing area where batteries can be removed from the truck and charged in racks while another battery is put in the truck and the truck is sent back to work requires less floor space than parking trucks while they charge.

Erect racks over the battery charging area. Battery charging areas require only 10 feet of head room. Pallet racks over these areas provide additional pallet storage.

Use double-deep pallet racks where feasible. If the pallet lot sizes are not large enough for floor or drive-in rack storage, consider using double-deep pallet racks for all items with normal inventory of at least two pallets. This would cut the space devoted to aisles by almost half compared with standard single-deep selective racks.

The primary drawback to the specialized racking systems is cost. Expect to pay two to 10 times as much per pallet position as you would for single deep racks. Ancillary costs, such as installation and fire protection systems, are also more expensive.

If your current facility has maxed out its expansion ability, the costs of moving to a larger facility must be compared to the marginal cost of the special rack system. In new construction, land costs may demand storage densification; environmentally controlled warehouse space also makes dense storage justifiable.

Put desks under decked rack sections. Desk space is necessary in every operation. By putting desks under racks, you can use the space above for storage.

Put the first set of beams at 7 ft. 6in. to 8 ft., then deck the rack completely and add lighting to create a mini-mezzanine.

Locate battery chargers between truck docks. Space between truck docks can be effectively utilized by placing battery chargers on wall space between docks.

Use horizontal carousels. By moving the shelf to the picker, horizontal carousels almost eliminate the picking aisle. The only aisle needed is the equivalent of a cross aisle in a conventional shelf storage layout. The carousel mechanism requires some space, but not as much as a picking aisle. This is an instance when collapsing the space may improve productivity by significantly reducing picker travel time.

Use overhead handling. Some products can be handled with overhead cranes from floor stacks with virtually no aisles. Because all handling takes place above the product, the only aisles needed would be for a person to walk to the material to attach the lifting device and space needed to connect the crane hook.

Before changing over to cranes and eliminating aisles, look at the consequences of the change. Sufficient height above the top of the storage must be left to transport the load. The ceiling must have clearance for the crane to travel without contacting drains, sprinklers or lights. The building must have the structural strength to support the crane and the load and the column spacing must be wide enough to allow a single crane to serve a large footprint. Because a crane can only travel between a set of columns, narrow column spacing requires more cranes and therefore more capital investment.

Operation ideas

Use random storage. Fixed storage locations force the warehouse to leave locations empty until stock is available. This results in empty locations while new material remains on the dock or in aisles until its home is cleared. In the extreme situation, the warehouse must be built to house the largest lot of every SKU, an obvious waste of space.

Stage outbound material in drive-in/drive-through racks. Instead of using dock space with single high pallets on the floor and wasted space above, use drive-in or drive-through racks with each lane assigned to a carrier.

Schedule deliveries and pickups to use dock space efficiently. Better used docks free space that can be used for bulk storage.

Use stackable totes for loose items. Place a number of totes on the same shelf. The totes should be sized on the basis of item size and quantity on hand.

Load outbound material directly into trucks. If truck arrival and order picking activities can be coordinated, the outbound material can be loaded directly onto trucks after picking, eliminating the need for a shipping staging area. Many carriers will cooperate by providing an empty trailer if the picking is done at night or if you have sufficient volume. If you limit the number of outbound LTL carriers, volume may justify the carriers dropping trailers at your dock.

Reduce the queue. The size of the queue is determined by two factors; how fast pieces are removed from it and how fast pieces are added. If the queue is in front of a bottleneck operation, little can be done to increase the velocity of removal from the queue. The clear implication is that the input side of the queue must be controlled. Non-bottleneck operations in front of the queue need to be slowed to correspond to the rate of the bottleneck.

Eliminate inbound inspection. The space needed for inbound inspection often represents the most under-utilized warehouse cube because material must be stored in a way that allows access to every unit to assure random selection of the sample.

Often, sample selection is a part-time activity for an inspector, resulting in large accumulation areas to compensate for less frequent sampling. Vendor certification programs that eliminate in-house inspection reduce the need for space to store material that is not available for production or sale.

Receive smaller quantities more often. This is the basic operating mode for just-in-time manufacturing. While the company may make long-term purchase commitments for specific SKUs, ask for ongoing deliveries that meet immediate production needs.

Move in-process inventory to the shop floor. From a process flow view, this eliminates extra handling needed to move work-in-progress in and out of the warehouse. It also improves the production cycle time. Putting the queue in front of the work station visibly identifies the bottleneck operations.

Check outbound material while picking or loading. If your operation requires checking prior to loading, have roving checkers check orders as soon as they are picked and just prior to loading. This eliminates the need for staging material that needs to be checked. If you are loading directly onto an outbound trailer, pallets can be dropped on the tail and checked just before loading.

Use slow time to put away and reorganize. Re-warehouse partials during slow periods each day. A warehouse management system that directs worker activity can take advantage of even short periods of slack time to direct the movement of partial loads to smaller storage locations. The system can be programmed to do this automatically during weekend day shifts when the rest of the warehouse is closed.

Reevaluate your dock usage. If it makes sense, move inside docks outside, then use the inside dock space to create additional storage space.

This article originally appeared in Productivity magazine, published by Pfingsten Publishing, LLC. Reprinted with permission. Contact Clair David Urbain, editorial director of Pfingsten Publishing at 920-691-1218.