An Order Fulfillment System or OFS is any system that assists
in fulfilling a customer order. In terms of this site it
refers to a system that depalletizes and then re-palletizes
product for shipment to a sales center. OFS systems can
vary greatly, and the only limitation to the size and complexity
of an OFS system is ones imagination.
As an example, let's consider a very simple OFS system, as
shown below. In practice, this may be too simple to every
put into practice, but it makes a good place to start our
discussion. As shown the robot "cell" consists
of a robot, a robot controller, a safety fence, two source
pallets, located near the top of our drawing, two destination
pallets located near the bottom of our drawing and a stack of
slip sheets, just to the right of center.
We will assume for the sake of argument that the two source
pallets each contain a different product. For our
discussion let's assume a beverage operation. We'll say
that source pallet 1 is a pallet of 24 pack cans. We'll
say that there are 96 cases per pallet. Source pallet 2
consists of 2 liter soda. There being 8, 2 liter
containers per case. We'll say that there are 48 cases per
pallet. We also need to make an assumption concerning the
robot. We'll assume that the robot can pick up only 1 case
per cycle.
A
customer (in this case a small grocery store) orders 32 cases
of 12pk cans and 16 cases of 2 liters. The order is
transferred to a computer (not shown) that computes the exact
x,y,z coordinates corresponding to the pickup position from
the source pallets and the exact x,y,z put down coordinates at
the destination pallet, of each and every case. This
"robot manager" transfers this list of pickup and
placement coordinates to the robot controller. The robot
controller takes the list and directs the robot to pick up the
first case from the source pallet, in this case pallet
1. After picking the case up, the robot physically
transfers it to destination pallet 1 (which is previously
empty). One by one, each case is picked up from the
source pallet and put down on the destination pallet, in
turn. When all 32 cases of cans are stacked, the robot
then starts retrieving cases from the pallet of 2
liters. After completing each "layer" (or
tier) of 2 liters, the robot retrieves a slip sheet (usually
cardboard) from the slip sheet pile, and lays it gently on top
of the first layer of 2 liter cases. This slip sheet
improve the stability of the load. After the slip sheet
has been laid down, the robot continues to stack the remaining
layer of 2 liter cases. When the layer is finished, the
order is complete. This pallet can be shipped to the
customer. When a new order comes in, the robot will
begin working to fulfill it.
Now that we've walked through the basic elements of an OFS
system, we can consider a larger system. Unlike the simple
system that had only two source pallets and two destination
pallets, this system has 64 source pallets and up to 32
destination pallets. The source pallets are located in a
"bin", where each bin can hold up to 3 pallets of the
same product type. Whenever, the robot depletes a pallet,
the pallet is removed and the 2nd case in the bin moves into the
primary position, and there are two source pallets (of that
product type) left. An indicator light will come on over
that bin, and a forklift operator will be dispatched to refill
the bin with another pallet, or an Automated Storage and
Retrieval System could be employed to refill the bin.
The system depicted below requires 4 robots, each mounted on
either an 'X' directional gantry, or some type of shuttle cart,
where it is free to move back and forth picking product from one
of its 16 source pallets, and then placing the case on the
destination pallet.
Again,
a "robot manager" computer system is required to
coordinate the stacking of orders onto the destination
pallets. The destination pallets move down a conveyor from
time to time, as the orders are filled. First being
stacked from robot 1 and 2, and then moving on to be stacked by
robot 3 and 4, depending upon the requirements of the order.
As orders are filled, the completed pallets move down and out of
the loading area, to be picked up by a fork lift operator or
they continue moving on the conveyor toward a stretch wrap
machine or other process machinery and/or labeling equipment.
So, an OFS system consists of the
following:
WMS - Warehouse Management System. This is the
system that has the customer orders.
Robot Manager. Computer system that takes the
orders provided by the WMS and creates a set of
instructions that the Robot Controller can understand.
Robot Controller(s). Proprietary control that is
purchased with the robot from the robot
manufacturer. This system controls every function
and action of the robot. It takes the case pickup /
placement instructions and actually controls the various
robot joints (motors) to achieve the Robot Manager
commands.
Robot(s). As many as needed. This could also
include the gantry or shuttle cart that moves the robot.
Source Pallets - Products that are sold
Destination Pallets - In process or completed orders
We could show many,
many different configurations of OFS systems here, but as with
the other pages on the site, our purpose is more to educate than
innundate. Our hope is that by showing the very simple and
the very complex, that you, the reader can get a good feel for
the types of systems that we are capable of delivering, and that
we are able to meet your needs, however simple or complex they
may be.
