Appendix
A Local Metaphor Model
Example
A structured
presentation of the salient features of a respected
process familiar to local people.
Assembly Lines Built JIT
Look through Fred Mauck's eyes for a
moment. You work in the GM stamping plant outside of
Pittsburgh that specializes in after-model-year body
parts. Your principal customer is GM's Service Parts
Organization. They might order '73 Chevelle hoods
quantity 50, '84 Chevy Impala right fenders quantity 100,
or '89 Cutlass Supreme right front doors quantity 300.
Your plant stamps the sheet metal and then assembles a
deliverable product. Small lots, high variety,
hard-to-make-a-buck stuff.
Every new part that the plant takes on
came from a production process at an OEM plant that
occupied some thousands of square feet on the average;
and the part was made with specialized equipment
optimized for high volume runs and custom built for that
part geometry. To stamp a new deck lid (trunk door) part
you bring in a new die set - maybe six or seven dies,
each the size of a full grown automobile, but weighing
considerably more. And you bring in assembly equipment
from an OEM line that might consist of a hemmer to fold
the edges of the stamped metal, perhaps a pre-hemmer for
a two-stage process, dedicated welding apparatus for
joining the inner lid to the outer lid, adhesive
equipment for applying mastic at part-specific locations,
piercer units for part-specific holes, and automated
custom material handling equipment for moving work
between process workstations.
You got a call a few weeks ago that
said your plant will start making the Celebrity deck
lids, and production has to start in 21 days. Not too bad
- sometimes you only have four days. For new business
like this your job is to get the necessary assembly
equipment from the OEM plant, reconfigure the equipment
and process to fit your plant, and have people ready to
produce quality parts in the next three weeks. Others are
responsible for the die sets and stamping end of the
production process.
In the last 12 months this happened 300
times. In the last five years you've recycled some
800,000 square feet of floor space in OEM plants for new
model production. At this point you have assembly
equipment and process for some 1000 different parts - but
no extra floor space ever came with any of it.
And no extra floor space materialized
in your plant either. Good thing you haven't needed it -
the core competency here is rapid new-part starts, and
small-lot, high-variety production - in a business that
is traditionally based on high volume economics - and
you've learned to do it without the usual capital budget.
Eight years at this has evolved some pretty unique
techniques - and a pretty unique culture as well.
You don't do this by yourself - you're
a team leader that may use almost anyone from anywhere in
the plant. At this point almost everyone is qualified to
help bring in new work - surviving under these conditions
has developed a can-do/let-me-at-it attitude almost
everywhere, and a shared understanding of how to do it.
Eight years ago the plant went to a
single job classification in production, cross training
everyone on everything - a press operator one day might
change dies as well, the next day work in the assembly
area building hoods in the morning and fenders in the
afternoon - and the following day go off to another plant
to review a piece of equipment or part for how to bring
it back.
For this new business Jim Lesniewski
wanted to do the initial recon. He went on the last trip
too, experimenting with his video camera. Now he thinks
he's ready to do a perfect taping job. He got the idea
himself while trying to bring several jobs at once back
from another GM facility. This environment encourages
self initiative.
In addition to taping the operational
assembly process he added close-ups of key equipment
pieces this time. In the debrief review everyone saw the
same thing at the same time - there was almost no debate
over what to bring back and what to ignore - and you got
a jump on the equipment modifications by seeing what was
needed in advance. Some time ago the value of having a
good cross section represented in these reviews became
evident: nobody gets surprised, everyone shares their
knowledge, and when the equipment arrives the
modification team is prepared.
Two keys at this stage: knowing what to
bring back and knowing what modifications to make.
This new deck lid would be handled by
bringing back the hemmer only; ignoring the mastic
application machine, two welding robots, the welding
fixtures, two press piercers, the shuttles, the press
welders, and the three automated material handling
fixtures. Basically bringing back a foot print of 200
square feet from a process that covered 2500 square feet.
The rest will go to salvage disposition while the hemmer
goes to "hemmer heaven" - that place in your
plant where some 200 different hemmers hang out until
needed.
That you only need the hemmer is where
a key part of the plant's unique core competency comes to
play. Rather than build a growing variety of product on
some sort of omnipotent universal assembly line, a line
that grows to accommodate next year's unpredictable new
business as well as the last ten-to-twenty years of
legacy parts, this plant builds a custom assembly line
for each product - and builds that assembly line just
before it runs a batch of, say, 300 hoods. When the hoods
are done you tear down the assembly line and build
another one for fenders, perhaps, on the same floor space
- and then run 500 or so fenders. Tear that down and
build the next, and so forth. The same people that built
the hoods build the fenders, and the deck lids, and the
doors, and the .... and tomorrow some of them will be
running a press, changing press dies, or running off to
evaluate the next incoming equipment opportunity.
Necessity is the mother of invention -
and the driving force here is the unrelenting requirement
to increase product variety - without increasing costs or
making capital investments. But fundamentally, for
assembly, the scarcest resource is floor space.
Yes - a newly built customized assembly
line for each and every small-batch run, every time, just
in time.
The plant has six assembly areas, and
can build any part in any of those areas. Usually you
like to do the deck lids in the "A" area,
though, as it has the most flexibility for welding.
While you were waiting for that new
hemmer to arrive you designed the process system
configuration. Betty Garrison and Denny Hanko usually do
this as a team. Once they figure out which assembly
modules are best and how they should be spaced, Betty and
Denny put together a configuration sheet for the assembly
system by cutting and pasting standard icons for each
module and running it through the copy machine.
It wasn't always this easy, but you've
learned a lot over the years. You build these assembly
systems according to the one-page configuration diagram
in Betty's three-ring binder - in real-time from reusable
modules. Modules are easily moved into place and they
share common interface standards and quick disconnects.
On the average it takes about 15 minutes to break down
the last assembly system and configure the next one.
First rule: Nothing is attached to the
floor permanently. If it can't be lifted and carried
easily by anybody it will have wheels on it, or as a last
resort, fork-lift notches.
A typical deck lid assembly sequence
might hem the outer skin, mastic some cushioning material
to the inner skin, then weld a brace into place, and
finally weld the inner skin to the outer skin in 30
places. In the process the material has to be turned over
once and some gauging is done. The assembly system
configuration might call for two three-foot roller tables
in the front to receive the inner and outer pieces -
think of these as hospital gurneys, on wheels, with
rollers on top so the "patient" can be rolled
across the table to the next station when the designated
operation is complete. Next in line for the outer skin is
the hemmer - it's on wheels too, and it's quick-connected
to a standard controller off on the side out of the way.
Yes, the controller is on wheels too. The outer skin is
lifted into the hemmer with the aid of an overhead TDA
Buddy - one advantage of doing lids in the "A"
area: two TDA Buddies hang from the ceiling grid. When
deck lids are assembled in another area a variant of the
roller table is used that includes lifting aids. After
hemming, inner and outer skins move to four-foot roller
tables under the welding guns. The configuration sheet
shows how many guns are active, where to position them,
and which tip variant to install. All told there might be
12 simple icons on the sheet positioned in a suggested
geometry.
A hemmer is a very specialized piece of
machinery. When it comes to this plant it loses most of
its specialness - and becomes plug compatible with all
the other modules in the just-in-time assembly family.
Importantly, the integrated controls are removed and
quick-connect ports installed to interface with the one
standard electronic/hydraulic controller used for all
hemmers. It is modified if necessary to work with one of
the six standard control programs. Maybe a seventh will
be added some day, but six has covered all needs so far.
Finally, the set-up sequence for the hemmer is typed up
and attached to its side - better there than in a file
drawer.
Hemmers are pooled in hemmer heaven
awaiting their time in the assembly area - each one being
individually part specific. Other pools hold variants of
standardized modules that have use in multiple assembly
systems: twelve different types of roller tables, two
types of quick-connect weld guns, three types of weld
tips, one standard controller type, six standard
downloadable controller programs, and other reusable
standardized items.
Whatever the configuration sheet shows
is quickly carried, rolled, or forked into place,
quick-connected or downloaded if required, and ready for
action. The assembly area has an overhead utility
framework that enables the adaptability below; providing
tracked weld-gun hookups, quick-connect power and air,
light, and water. The operating atmosphere is not unlike
the hospital operating room - except patient throughput
is a lot faster - fast enough in this case to satisfy
service parts economics.
It is common for production team
members to make real-time changes to the configuration
when they find a better way - better is better, and
everyone knows what that means.
Rule two: People rule. These assembly systems
take advantage of the fact that people think better and
adjust better than automated positioning devices,
cast-in-stone configuration sheets, and ivory-tower
industrial engineers. People bring flexibility when they
are enabled and supported, but not constrained, by
mechanical and electronic aids.
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