put-to-light display unit moves on a track
behind it so that the container and display
are traveling in concert. The system reads
RFID tags attached to each display unit
as it enters a zone. This causes lights and
quantity displays to illuminate at a flow-rack position to indicate which frozen
product should be picked from that zone,
and in what quantity. The worker gathers
the prescribed number of items and turns
around to look at the containers rolling
through his or her zone.
Some of the displays riding along behind
the delivery containers will then illuminate with a quantity indicator, which tells
the worker which containers require that
product, and how many items to put into
each one. There are two lamps on the
display. One lamp indicates to the worker
that the container requires a product in
his or her zone, while the other lamp indicates to workers a little further down the
line whether a product will be placed in
the container in their zone, which allows
them to have those items ready before the
container arrives.
Workers also wear a battery and RFID
reader on the waist, and an antenna in
a fingerless glove that wraps around the
hand. As the order picker gathers the
items, the antenna reads the RFID tag on
the shelf to ensure the correct item was
picked. When he or she reaches into the
container to deposit the required items,
the wrist antenna gathers data from the
tag on the display unit to confirm that
the item has been placed into the correct
container. So essentially, the RFID tag
replaces the need to hit a confirmation
button, as is commonly done with light-based systems.
The light-directed system is an effective choice here. While temperatures in
the pick zones are not as cold as in the
freezer, workers still must don hats and
gloves. Using lights eliminates fumbling
to press keys or cross off items on paper
lists. Plus, it is faster and more accurate,
and the light displays perform well in the
cool environment.
The containers continue to pass
through all zones until they reach the
end of the line, where the displays drive
an order-confirmation process designed
to verify that the total number of items
placed into the container is correct.
The light displays direct three people
to perform this process by showing
one of three colors: red, yellow, or
blue. Each worker is assigned to
count items only in the containers
displaying his or her assigned color;
this eliminates any potential confu-
sion about which container to check
and helps to keep the line moving at
the required speed. The display also
shows the total quantity of items
that should be in that delivery con-
tainer. The workers count the items
in the assigned containers, and if the
count matches the display, they then
