Latest Trends in Pick to Light Systems
Latest Trends in Pick to Light Systems
The picking information design can be an
important factor concerning picking accuracy, picking productivity and how the
picking work is perceived. There are different ways to design the information
system, in which the picker receives and understands the information regarding
which parts to pick for each order. Some of them are explained below:
# Traditional
picking
·
Information reaches the picker
in form of a Pick list specifying identification, nos., location, etc., of
parts to be picked. Usually the picker manually ticks off the parts after
picking them.
·
Designed for beginners making
experienced pickers neglecting the pick list, just picking by experience. This
may cause problems during design changes, new part introduction, etc. and even
if the picker is not using the pick list, time must be allowed to the picker
for reading and identification.
·
This system’s benefit is that
it requires quite small investment since most often a similar system most often
already exist in the warehouse.
# Number or
Colour
·
Each variant of final product
has a number and when picking, the picker looks for this number on a variant
scheme at every storage location. A different approach to this idea is using colours
instead of numbers, i.e., the picker receives a colour and then continues to
pick parts at every storage location with the same colour.
·
Requires dedicated storage area
for every part & frequent update when parts are moved, change or taken
away.
# Screens
·
The picking information is
displayed on a screen placed in the picking truck telling the picker what,
where and how many components shall be picked. This system requires a
relatively big investment in hardware and software.
# Product
Info
The picker only receives the product
specification and from that through experience and work sheets knows what parts
to pick. This system benefits from its simplicity, but it demands experienced
pickers and non-frequent product design changes.
# Pick-to-Light
·
Use of small lamps (light
modules) at storage location showing when a specific part shall be picked, and
a display shows how many to pick. In some cases, there is a push button for the
operator to push when the part has been picked. The kit can’t be sent away
unless all buttons have been pushed.
·
This system ensures minimum
picking errors.
·
Require relatively big
investments in hardware and software
Critical Success Factors for Pick to Lights –
· - Modularity of hardware – should
be compatible for different environment and plug n play type
· - Robust & quick installation
· - Simple software – should
support customization as per application area
Basic Infrastructure of a traditional pick to light
setup –
1.
Main
Controller & HMI – this is the main
controller which interacts with the plant broadcast system and directs the
subcomponents
2.
Intermediate
Controller – this device are junction boxes or
fieldbus controls which triggers the individual lights
3.
Connections
– these are the wirings/cables which connect the
lights to the controller. Things have improved now from the traditional
individually wired lights to end connected ducts which allows plug n play
lights.
4.
Lights – these are the indicators and comes in various types. Apart from
the basic single colour push button types we can find multi-colour options to
define different stages of the process (ready to pick, in pick, pick complete,
etc) and with digital displays to show pick quantity. We also have the lights
with light curtains and sensors to avoid touch.
Further innovation can be
lights with motion sensor which is briefed later in this article.
Manual picking of parts from marketplace
which was error prone. (Wrong Part Pick, Missing part in Kits, Wrong Quantity
pick and Miss-Build at assembly line). This triggered to look for a solution which
evolved the Digital Part Pick system or Pick to Light system which eliminates
the manual errors in picking.
With the growing technology lot of new
innovative systems have emerged which are slowly gaining popularity. Some of
these latest trends are covered in this article.
A.
Pick to lights with Motion Sensor –
Pick to lights with light curtains or
sensors work on the same standard principle as light buttons where operator
view the glowing lights but instead of pressing button the light senses the
hand movement while operator picks the part and acknowledge by dimming the
light.
Problem with this setup is that it does not
stop the operator to pick from a location where light was not on or where it
was not supposed to be picked.
Motion sensors can help in addressing this
by having a buzzer or horn to alert during wrong pick. It can also be useful to
some extent for securing the pilferable parts.
B.
Projection Picking
It works on image processing technology
& may not necessarily need the physical lights to be installed. But it can
be integrated with the light modules as well.
It projects an image of the part to be picked or even the assembly
process to guide the operator on how and where to place or assemble the part
(in case of picking done online).
Instead of physical light buttons the
system can project a flashing light or even the part number or name on the
corresponding part location. Even wrong picking can be avoided by providing a
warning light projection.
For more details on projection picking, you
can check the offering from AIOI, Japan
Major benefit of this is the elimination of
electrical wiring and proving simpler installation. It will be interesting to
study a business case based on the application area, physical feasibility and
number of parts to handle.
C.
Put to Light
When it comes to preparing a work order in
sequence involving multiple parts, put to light can be the right option to error
proof the process. It is an extension of pick to light where the lights also
guide the operator to suggest the correct bin or slot on the bin/rack where the
part need to be placed.
A classic use case is for Sequencing of items
with high complexity.
D.
E-Labels
E-labels, or E-ink tags or E-paper or SMART
cards are like ID cards with digital display. It can display barcode, part
information (part name, quantity, etc). E-labels enabled with a touch option
can be used as a wireless pick to light. They also come in colour options which
can give a better visual.
Key benefits will be -
·
Environment friendly being
paperless
·
No wiring infrastructure
·
Ease of configuration and real
time update
The most critical aspect to use the
E-labels will be the wireless connectivity. Recent trends show their use in
supermarket shelves and use either RFID or Bluetooth technology.
E.
Wireless Light Modules
The biggest challenge in any pick to light
setup is accommodating changes in bill of material which calls for physical
rearrangement of the facility, shelves or expanding the area. Wireless light
modules can give a big relief as they could provide a quick setup in available
space or using a temporary location. Like E-labels, wireless light modules can
also reduce installation cost depending on the low radio frequency or Bluetooth
connectivity instead of traditional Wi-Fi network, but Wi-Fi does have its own
benefits in terms of a common network coverage across the site.
Basic Infrastructure Setup may look like as
below
F.
Mobile based configuration
Traditional pick lights need configuration
either using a light address setup device or physical setup linking each light
with controller which is tedious. Recently trends include an easy setup done
using mobile or a handheld scanner.
References
–
https://www.turck.in/en/2644.php
https://www.bannerengineering.com/us/en.html
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