38 DC VELOCITY MARCH 2017 www.dcvelocity.com
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these functional areas into the clean environments without
slowing down production or contaminating the processing
areas. Because contamination is often transmitted through
people, limiting human touches was an important part of
the solution.
“We wanted to prevent having people moving back and
forth between the warehouse and the manufacturing area
because each time they would enter manufacturing, they’d
be required to gown-up,” says Dave DeVries, principal
engineer.
To minimize human involvement, Amway invested in
a fleet of five automated guided
vehicles (AGVs) from material handling and logistics systems provider
Dematic. The AGVs handle most of
the intraplant material moves, taking products in and out of storage
and ferrying them to manufacturing areas. Although there are some
limits to where they may go in the
facility—for instance, the AGVs do
not venture into any areas where
raw materials are processed or into
rooms with open product containers—they’re still able to handle much of the intraplant
transport work.
Dematic also implemented a warehouse execution system
(WES) to manage the flow of goods as well as an integrated equipment management system (EMS) to control the
AGVs’ movement. Working with Dematic is convenient for
Amway, as Dematic’s North American operations are based
in nearby Grand Rapids. In fact, the two companies have
worked together on many projects in the past.
LEAN AND CLEAN
The quality control process that guides every aspect of the
work at Spaulding starts in receiving. As ingredients for the
supplements—like gelatin, glycerin, and fish oils—arrive at
the facility’s 10 truck docks, workers load the drums, boxes,
and sacks onto plastic pallets supplied by Gorilla Pallets.
Plastic pallets were chosen both for reasons of hygiene and
because they have the consistent dimensions required for
use with AGVs.
Two forklifts (supplied by UniCarriers) gather the pallet
loads from the docks for transport to a receiving rack system that holds 52 pallets—about the number contained in
one incoming truckload. The rack serves as a transfer point
between the dock and the warehouse, with all forklift traffic
restricted to the dock side while the AGVs operate on the
other side. The receiving rack is one pallet position deep
and four levels high, and is accessible from both sides.
The forklift operator first locates an open rack position.
He then scans the pallet ID and a rack location bar code to
assign the pallet to a particular slot. The scans automatically
notify the WES of the products’ temporary location.
The forklift operator then places the load into the rack
position. Mechanical guides built into the racks assure that
the pallets are placed precisely into the slots. That makes it
easier for the AGVs to retrieve the loads from the opposite
side of the racking.
The WES coordinates with the EMS to control the AGVs.
It uses a “look for work” algorithm, whereby the software
matches an AGV with a task based on the vehicle’s location,
receiving rack. Each AGV’s forks are
able to reach up to 18 feet high, so
the units can easily access any of the
pallet positions within the four-level
racks.
The laser-guided AGVs navigate
using a rotating sensor attached to
Two other laser sensors (supplied by sensor manufacturer Sick) also check for obstacles and will stop the AGV if
they detect a person or object in its path. They even “look”
around corners as they approach a turn to make certain the
route is clear. DeVries reports that the safety features have
worked flawlessly, noting that all workers in the facility have
also been trained to be aware of AGVs working nearby.
