Autonomation
 Autonomation transfers a level of
human intelligence to automated machinery. Machines thus detect
even a single defective part and immediately stop while asking for
help.
The concept was pioneered by Sakichi Toyoda at the turn of
the twentieth century. He invented automatic looms that
stopped instantly when any thread broke. This permitted one operator to
oversee many machines without risk of producing large amounts of
defective cloth.
Taiichi
Ohno considered Jidoka (Autonomation is one variant) as one of the
two pillars of the Toyota Production System.
So,
What's The Big Deal?
This
sort of interlock is commonplace today and we take it for granted.
Modern equipment has many types of sensors to detect broken tools,
jams, defects and other abnormal conditions.
However,
in the 1950's, 1960's and 1970's, automation relied on relay logic
and often required a human operator to detect abnormalities. This
limited the benefits of automation
Even
in the 1950's interlocks, such as the simple limit switch
illustrated above, were available. What
differed at Toyota was the extent of their use. Like
many of Taiichi Ohno's methods, this is a
simple
idea that he pursued for decades until it became a strategic
competitive advantage.
|
This
illustration shows how a limit switch stops Operation #10 when the
transfer conveyor has five pieces.
The
Role of Autonomation
Autonomation
is an important component of Lean Manufacturing Strategy for
high-production, low- variety operations, particularly where product
life cycles are measured in years or decades.
In
high-variety, low-volume situations, the time and effort required is
prohibitive. This is another example of how lean principles must be
tailored to each situation.
References
MONDEN,
YASUHIRO, Toyota Production System, Third Edition, Industrial Engineering &
Management Press, Atlanta, Georgia, USA, 1998.
HARRIMAN,
FRED, http://www.fredharriman.com/resources/documents/FHcom_Kaizen_Terminology_03.pdf,
2000.
OHNO,
TAIICHI, Toyota Production System- Beyond Large Scale Production,
Productivity Press, 1988.
SPEAR,
STEVEN, The Essence of Just In Time, http://www.hbs.edu/research/facpubs/workingpapers/papers2/0102/02-020.pdf |
