Product Description
The rise of Jidoka in lean manufacturing
Over the last 80 years or
so, Japan's manufacturing processes have been responsible for how the Western
world has begun to approach how it manufactures and manages its manufacturing
industries. Many methodologies like Toyota's Production
System & Lean have been around for some time. But relatively recently, new techniques such
as Kanban, Andon, Just In Time, and the Pull System, etc, have gently crept
into everyday business terminology - particularly in company board rooms and
shop floors throughout manufacturing fraternity.
One expression or word
which has arisen from Japanese manufacturing production practices is
Jidoka. Toyota's Production System,
(which was studied by Rosenthal in 2002) frequently pictured possessing 2
pillars - with one of them called Just in Time and the other one labelled
Jidoka.
You can find a number of
definitions for the word. In 1999,
Standard & Davis translated Jidoka to indicate
"quality-at-source", with Imai referring to it as "autonomation"
in 1986. The Japanese language suggests
2 different definitions for jidoka - one of these is "automation" -
which explains that it's a manual process that is converted into a machine
process. The second definition is an
"automatic control of defects" which recognises the human intellect to
identify, troubleshoot problems and rectify failures in a process
The Toyota Group refers to
Jidoka as "Ninbennoaru Jidoka" or simply translated in English as
automation with a human mind. Essentially this means that it's a technique or
strategy to detect and correct manufacturing defects, which includes the
following characteristics:
A method that reveals
defects or abnormalities; and
A system that stops
production or machinery when a defect or an abnormality arises.
2 methods can halt a
production line. One way involves a production worker's personal judgement and
the other one where machinery shuts itself down with an in-built automatic
device.
The first technique needs
management to empower production staff to close down production and deal with
issues as they arise. The 'tool' most
frequently applied to close down production by production staff is called
"andon". Basically, an andon
system brings the production line to a halt and signals to everyone on the shop
floor that something's wrong which requires immediate attention. The problem is then typically looked at by a
group of individuals.
A tool used for shutting
down machinery as part of the Jidoka system is "poka yoke". In
manufacturing environments, Poka yoke, alternatively called 'mistake-proofing',
is a system to ensure that defects can's arise.
Common poka yoke examples may include devices like lasers, automatic
switches and jigs, etc. When a fault or
defect is detected or when a pre-specified quantity of a product's made, a
warning signal is transmitted the machinery to switch off. This practice allows
production staff to look after more than one piece of machinery at a time.
One example of how Jidoka
is used in practice is adopted by Toyota.
Situated between processes is a custom designed mat that is similar to
those that activate the doors to which open at major retail outlets. For optimum efficiency, the production line
moves at a steady speed. If a production worker doesn't or can't complete their
task in predetermined timeframes, they will jump on the nearest mat, which will
close the line down. This will centre
everyone's attention and then his section to identify why it's taking him much
longer than expected. Another case would
be limit switches and lasers that sense various components or parts normal
length. If these parts don't match pre-
programmed settings, a warning signal would be transmitted to trigger the
production line to immediately stop and production staff will start to tackle
the problem.
