40 NEWEQUIPMENT.COM I APRIL 2017
by Richard Barnes, Wipro Ltd.
As consumer product companies go digital with orders coming from a growing list of omni-channel sources, order profiles are evolving rapidly. Oftentimes these
profiles are reduced to just a few items per order. To meet
these changing demands, digital distribution centers are
reviewing their picking methodologies to improve efficiency
and to quickly get orders on their way to the customer.
Several order picking processes exist that can be deployed in a digital distribution environment, which can be
divided into four major categories: discrete order, cluster, zone, and batch picking. Choosing the correct picking
strategy for your center depends on a variety of factors,
including order size, warehouse size and business need. By
taking into consideration the advantages, disadvantages
and best practices for each option, your organization can
ensure its picking system meets the demands of your digital
1. DISCRETE ORDER PICKING
In a normal distribution center, discrete order picking is
the most commonly used picking process. This type of picking is used for one order at a time, with the picker walking
the entire picking area for each order. Discrete order picking
has the advantage of being simple to learn as well as being
accurate even without using a warehouse management
software (WMS) system.
For wholesale companies receiving large-cube orders, this
process is highly effective, but, is very inefficient for small
cube items, because each order requires an employee to
make a trip through the entire forward pick area and return
to home-base after each order is picked.
Discrete order picking should be considered for digital
distribution only when processing items with large cubic
dimensions, when your operation does not have a WMS
system and accuracy is a critical business requirement.
If your digital distribution center is receiving many small
orders or is simply too large for this one-at-a-time picking
method, an evolution to a more flexible picking process may
be your best option.
2. CLUSTER PICKING
The next step up in efficiency is cluster picking. In cluster
picking, multiple orders are picked during a single pass
through the forward pick area; the items are picked and
then placed by order into containers. The picker will take
multiple orders through a single pass of the warehouse,
thus multiplying efficiency by minimizing trips through the
Cluster picking can be achieved more effectively by using
a WMS system. The WMS directs pickers through the pick
area displaying what to pick and which container to place
the item into for the corresponding order. This can also
happen in a paper-based warehouse when pick-lists are
pre-printed and then manually sorted for like items in the
pick area. Paper-based cluster picking is less accurate as
pickers may pick or place the wrong item into an order as
then try to manage many pick-lists, often a post pick quality
control check is used to ensure accuracy – costing efficiency
as another process is engaged.
Cluster picking is most appropriate for Digital Distribution when handling orders with small cubic dimensions or
when your distribution center/pick area is small enough
for a picker to efficiently walk through. It also helps to have
a WMS system that can direct the picking and putting of
many orders at one time in an efficient path.
3. ZONE PICKING
To minimize walk-
ing the whole pick
area, zone picking is
used when the entire
pick area can be bro-
ken up into smaller ef-
ficient picking zones.
Cluster picking is still
used with zone pick-
ing to maintain the
efficiency of picking
multiple orders. When orders can be picked into shippa-
ble containers, zone picking has the double advantage of
reducing the walking while shipping the container as soon
as picking is complete. Zone picking typically requires a
complex zone routing conveyor system controlled through
a WMS system.
Zone picking should be considered for Digital Distribution when picking items with a variety of sizes, shapes,
and storage climate requires the distribution center to be
broken into walkable pick zones, and when an appropriate
conveyor and WMS are in place.
4. BATCH PICKING
The next step in improving efficiency is when a small
number of items are required on many orders through a
batch picking process. Batch picking is used when the entire
quantity of an item is picked per wave (or batch) and then
consolidated with the rest of items for the order. Batch
picking is usually used with other forms of picking (Cluster
and Zone) for the slower moving items of the order. Consolidation can happen using an off-line Put-Wall process or
a complex sortation systems.
Batch picking is the best option for Digital Distribution
when a small number of items (web-promotional items) are
common across a large number of orders. It is also best
used when automation can be justified by the reduction
of employees to process orders in the distribution center.
The transformation to a digital company means order
profiles will continue to change, lowering the number of
lines per order as consumers order only what they need at
that point in time. As the number of lines per order changes,
so will the requirements for picking those orders. Picking
professionals will need to transform the distribution center
and the picking strategies with the changing requirements
to meet the demands of the Digital Distribution age.
Four Picking Options for Your Digital Order Profile
Sorting and moving materials and goods in the distribution center can eat up a lot of your logistics budget.
The right picking solution can make a big difference.