Less-Than-full Pallet Methodology: Pick-to-belt or Pick-to-pallet?

There is an old maxim in the consulting business that if you ask two consultants the same question, you get four answers. Not being one to shatter a stereotype, the answer to the title question is not a direct one. Rather, it requires some navigation of the issues that would suggest one methodology over the other.
Beverage distributors who are dealing in less-than-full pallet or layer quantities employ one of two general methods to select individual cases or retail units: Selection onto a pallet being transported with a pallet jack (a.k.a. “pick-to-pallet”); or a method known as “pick-to-belt,” in which an order-selector places individual cases or totes onto a conveyor for transport to a sortation and palletization area.
When I first began my career in the warehousing business, “mechanized systems” were the concepts of fancy. The notion of modern conveyors and sortation devices humming endlessly, whisking cases from the item’s home slot to be stacked on the truck for outbound delivery, made both warehouse managers and chief financial officers get misty-eyed over the “savings” these systems were providing.
It wasn’t that long ago that warehousing executives were criss-crossing the country to observe the latest conveyor belts that would extend into a shipping trailer for case loading, or the system that utilizes blinking lights on the rack to indicate the location and quantity of cases to be selected for placement onto the takeaway conveyor belt.
The standard configuration calls for approximately three to four layers of selection mezzanine serviced by numerous aisles of reserve inventory. Order selectors pick cases onto conveyor belts, applying selection labels while doing so.
Typically, this is done in a “batch mode,” wherein the selector picks cases for multiple customers simultaneously.
Cases are conveyed to a sortation system that separates orders by outbound truck (or customer, depending upon the condition) and the case is either floor stacked onto the truck or palletized for outbound delivery. The limit of how many customers can be selected simultaneously is usually determined by the number of palletization stations.
While touting the virtues of such a system, a nameless salesperson comes to mind who uttered the classic, “No pick-to-pallet process will ever come close to our productivity; we’re getting 450 cases per hour.”
Impressive, no? In fact, the salesman was telling the absolute truth. What he failed to mention was that the performance quota was merely the rate for putting the cases on the conveyor belt at the selection slot; he did not include the rate for taking them off at the shipping dock for stacking onto a pallet or route truck floor.
Performance for removal of cases is roughly the same as selection, so if we’re selecting at 450 cases per hour and palletizing at the other end at 450 cases per hour, the gross performance of the selection process is 225 cases per hour for a completed pallet. This is still an impressive productivity number, but not the touted 450 cases per hour.
As the above-described systems continue to propagate, conventional, non-mechanized operators continue to push for tools and processes that will help them in their effort to become more efficient. They are working to match the productivity benefits offered by suppliers who install mechanized solutions.
Among the advancements for conventional operators are double- and triple-position pallet jacks, paperless RF voice selection, engineered labor standards, productivity-based cash incentives, and assignment-specific performance targets, to name a few.
The list goes on but the result of these and other advancements is that a 225 crew average for selection cases per hour is now being achieved on a regular basis with conventional pick-to-pallet systems. This performance parity is based solely on selection; the replenishment process for the mechanized system is an entirely different story. It essentially requires a three-step process. One operator selects cases from a reserve slot, the next operator transports those cases to the prescribed level within the system where the selection slot resides, and the final operator transports the cases via catwalk to deposit them in their respective slots.
Suffice to say that the expense of performing the receiving and replenishment tasks are nothing short of a nightmare.
Early in this commentary I mentioned that the previous is targeted to distributors who are typically shipping less than a layer of any given SKU. For those who are shipping by layer, the mechanized suppliers have pushed the state-of-the-art and are now regularly automating both the selection of a layer of like product and the palletization of those layers for outbound shipment.
This has become a tremendous opportunity for manufacturers and distributors to respond to a customer’s specialized needs. With this system, display, promotional, or “rainbow” pallets can be automatically assembled to the specification of the customer.
As “Fortune 1 companies” (i.e., Wal-Mart) push the envelope to reduce the cost of delivered goods, manufacturers and distributors are responding with the requirement that entire layers of an item be ordered. As a result, the benefits of automated order selection and palletization can be completely realized by all.
For the one- and two-case orders, our clients are resoundingly shifting away from mechanized selection and toward pallet jack, floor-based case and bottle selection onto pallets. Among the reasons are:
The ability to add labor in the form of pallet jacks and order selectors during peak periods. With sufficiently wide selection aisles, order selectors can pass one another and multiple employees can work in the same area.
Streamlined, floor-level replenish- ment processes. Gone is the requirement for slots to be replen- ished utilizing elevated order pickers (PIR) or suspended mez- zanines with catwalks. With the floor-based, non-conveyorized model, reserve pallets are stored directly above the selection slot with forklifts that are able to refill slots on demand.
Eliminating “zone” style selection that is mandatory with pick-to- belt processes. Everyone works until his assignment is complete. With pallet-jack selection, there is no need to discontinue all selection  in the system while the slowest individual finishes.
Single-person, assignment- specific order accuracy account ability.
The bottom line? For those who are in a position to ship full layers to a customer, automation is not yet a viable proposition. While strides are being made, a magic solution that makes single-case, mechanized selection viable has not yet emerged.
For the less-than-layer orders of a specific SKU, we recommend a floor-based pick-to-pallet system utilizing pallet jacks and order selectors. In fact, our most recent beverage client incorporated both full-case and individual bottle selection into their pick-to-pallet process.
John B. McGlasson is vice president of logistics for Food Tech Structures LLC, a planning, engineering and construction firm based in Hanover, Mass., and manager of Food Tech’s West Coast office in Los Angeles. He has more than 20 years experience in the distribution industry, specializing in conventional and automated facility planning, and the development of distribution strategies to achieve maximum logistics return on investment. John can be reached at 310/980-4204, or by email at jmcglasson@foodtechstructures.com.