items to pick from the box. Since the tops of the boxes were
removed at receiving, the products, most of which are folded garments in polybags, are easily retrieved.
Workers use both hands, quickly alternating, to select
items one at a time from the source box. They place each
product onto an induction conveyor belt within the station
that feeds the sorter. A sensor detects the motion of the
worker’s hands as items are pulled out of the source box,
This design makes it possible for just a
few workers to select 3,600 pieces an hour
from about 900 source boxes, on average.
Once the items needed for orders have
been removed from the source box, the
box is conveyed to one of two intermediate picking storage buffers located nearby.
The two buffers have three aisles each and
are served by automated cranes. This area
has a total of 10,800 storage locations and
can hold the boxes on their trays three
deep. The boxes will be held in this buffer until the products
are needed. This same buffer is also used to temporarily
hold finished customer cartons until they are sequenced to
shipping. The cranes serving the intermediate picking
buffer can perform 1,400 moves per hour.
SORT CIRCUIT
The facility’s warehouse management system, also provided
by SSI Schaefer, coordinates the sorting of items so that all
sizes of an SKU are packed together to make store putaway
faster.
“When it arrives at the store, it is ready to put on sale,”
explains Castresana. “This puts the strain on the warehouse,
but we would rather do that than put strain on the store,
where the labor is more expensive.”
Belt conveyors transport the items from the pick stations
to the facility’s split-tray sorter. The conveyors act as buffers
to regulate the flow of goods into the sorter without slow-
ing down the picking process preceding it. The sorter con-
sists of 70 trays moving in a circular train. Upon approach,
the items are automatically scanned so the system knows
which item will be placed onto a particular sorter tray.
About 87 percent of all goods in the facility can pass
through the sorter, with the remainder handled manually.
The conveyor carries the product above the sorter, and at
the precise moment the assigned tray passes below, the belt
rolls to gently drop the product into the tray.
The sorter trays are hinged on the sides and split in the
middle, similar to bomb bay doors, so they can quickly
open to deliver products into 54 staging chutes located
below. As the tray approaches the chute to which the order
is assigned, the tray splits, gently depositing the item into
the chute. Each chute will gather items from several different trays, depending on the size of the order.
Underneath the staging chutes, conveyors carry order cartons that will ship to
stores and Desigual’s other channel customers. The chutes act as a synchronized
buffer between the sorter and order cartons, with products held within each
chute until the carton destined for those
goods is indexed below. At that point, split
doors on the bottom of the chute open to
deposit the garments into the order carton. The cartons will then continue to
progress along the row of chutes, with
more items added from other chutes to
complete the order. In a sense, the chutes
provide a secondary level of sorting.
Completed cartons are transported to an area where they
are labeled and stapled closed. They are then sent either
directly to the outbound docks or to the buffer AS/RS until
ready to ship.
A UNIQUE COMBINATION
The combination of the ergonomic picking-induction stations, the trays for sorting, the chutes for staging and performing a secondary sort, and the movement of cartons
below allows for very high sorting rates in a very limited
footprint. All of these movements are coordinated with
sophisticated software that enables the system to perform
9,000 sorts per hour, while managing 4,000 orders simultaneously and utilizing only the 54 physical chutes of the
system.
Castresana notes that while this sorter solution uses standard components found in other systems, the components
have never been put together in this exact way before. The
unique combination serves the demands at Desigual well.
“The sorter is the key point,” he says. “We did not intend
to discover something new, but this works for us. In the
end, the automation was the best solution. It gives us con-
trol, security, and the best performance for our demand.”
Unique enough to match its name – Desigual. ●
