as volume, fader, and channel knobs
and encoders are inspected for durability after more than 100,000 turns
and presses on an automatic machine.
Other tests conducted include drop
tests, vibration tests to simulate transport, and an operation check in extreme
weather conditions (hot and cold temperatures and other variables such as
humidity).
cial Audio production team met this
challenge by employing the “cell production” methodology. As opposed to
a typical “assembly line” where each
worker in the line is responsible for a
limited number of tasks or procedures
of the assembly process, small teams of
workers each work in a “cell,” where the
team is responsible for the entire process involved in the production of the
product. The number of workers in a
jigs or tools that may speed up production. In fact, “kaizen” (Japanese word
that literally means improvement) meetings are held regularly by cell workers
to make suggestions that may help production, from cutting down production
time, to reducing wasted materials.
Parts received from external suppliers must pass testing at the Toyooka factory Quality Assurance Center before
they can be accepted as stock or passed
STAGE 5: PRE-PRODUCTION
After minor design changes on the
prototypes have proven to clear regulations and Yamaha internal standards,
pre-production samples are made at the
final production facility using the same
production lines and the same staff.
The production team and the production engineering team become heavily
involved with the product at this stage
and work closely with the engineers
to prepare for mass production. The
assembly process is examined and perfected, while jigs are created to further
enhance assembly speed and quality at
the mass production stage. The pre-production samples are used for final
measurements to apply for various
safety regulations.
Rear and front panel production assembly is shown here,
which also takes place at the Toyooka facility.
STAGE 6: PRODUCTION
The majority of Yamaha Commercial
Audio products are produced at the
Toyooka factory located right outside
of Hamamatsu City in Japan. Contrary
to popular belief and most other manufacturers, the products are not built
by automated machines, but rather by
hand, by trained personnel. Compared
to Yamaha’s consumer products such as
digital keyboards or synthesizers, total
production quantity of Commercial
Audio products is much smaller, yet the
product lineup is wider. The products
are not “custom-shop” products and are
reproduced in bulk quantities to ensure
uniform performance.
The Toyooka factory Commer-
cell depends on the size and complexity of the product, but normally a team
of three-to-seven workers is responsible
for retrieving necessary parts from the
stockyard and assembling, inspecting,
and packaging of the product.
All cell workers require much education since each member is involved in
the entire production process. Though
it may require a longer learning curve,
cell production has proven to be much
more efficient once all skills have been
acquired. Each worker has a great sense
of pride in manufacturing the world’s
most acclaimed audio products. Cell
production is also beneficial because of
its flexible setup; for example, cells can
be dismantled and setup quickly with
different configurations to meet changing production needs. A cell member
can easily modify the cell setup to create a more convenient and comfortable
working environment or suggest new
on to the assembly staff. If a sample
from an incoming shipment does not
meet specified standards, the entire lot
will be returned to the supplier. Testing
at this stage is rigorous, extending to
details like finish durability and micron-tolerance dimensional precision. With
cooperation from the parts suppliers,
component parts inventory is kept to
a minimum at the Toyooka factory to
prevent deterioration. In addition to
cell inspection and testing of every unit
produced, samples are taken from every
production run for even more in-depth
testing. Computer-generated signal
sources are used, as well as standard
music sources to aurally check sound
quality and performance in ways that
test equipment cannot. All functions
are carefully checked as well.
Seiji Kurauchi works for Yamaha Commercial Audio Japan.
