RULES OF TOYOTA
Specifications document all work
processes and include content,
sequence, timing and outcome.
- The person or machine can perform
the work as specified
- If the
work is done as specified; the
product is defect-free.
- The work procedure varies from
- Defective Products
- Improve training
- Modify the work specification
Connections with clear YES/NO
signals directly link every customer
- Customer requests have a known,
specific volume and mix.
supplier can respond to requests.
- Responses do not keep pace with
- Supplier is idle
waiting for requests.
- Determine true mix and demand.
Determine true supplier capability.
- Retrain/ improve/ modify.
Every product and service travels a
single, simple and direct flow path.
- Every supplier in the flow path is
required and suppliers not on the
flow path are not required
- A person or machine is not needed.
- Unspecified supplier performs
- Determine why supplier was
unnecessary; redesign flow.
Determine reason for unspecified
supplier; redesign flow.
Workers at the lowest feasible
level, guided by a teacher (Sensei),
improve their own work processes.
- A specific change causes a
specific, predictable improvement in
productivity, quality or other
- Actual result varies from expected
- Determine why the actual result
differed from the prediction.
-Redesign the change.
Integrated failure tests
automatically signal deviations for
every activity, connection & flow
- Automatic alarms prevent defects
or sub- standard performance.
- Defects are passed through to the
- Analyze and institute new or
Rule # 1
document all work processes and include
content, sequence, timing and outcome.
Rule #1 is one of the
most important and least understood of the
rules. At Toyota, each process is
specified with detailed instructions. For
example, when assemblers install seats with
four bolts, the bolts are inserted and
tightened in a precise sequence. Every
worker installs them in the same way, every
increases the linkage between the way work
is done and the results. If everyone
worked in different ways, the link would be
broken or obscure. How do we reconcile such
regimented work with the experimentation and
concern for individuals that is supposed to
be a part of the system? The answer is that
while individual workers cannot vary the
process, teams are required to actively
analyze experiment, change and improve the
Rule #1 links closely
with the widespread use of TQM, SPC and
associated problem-solving skills. If
workers do not possess those skills, Rule #1
is pretty much worthless and even
This is often seen in an
insistence on detail work instructions.
Detailed work instructions are all very well
if the process is stable and/or workers have
an adequate TQM background.
What usually happens
is that engineers write unrealistic
instructions with little input from workers.
Nobody involved has an adequate TQM
background. Workers cannot follow the
instructions and they are promptly ignored.
There is little feedback to the authors. The
authors are busy writing new work
instructions for other parts that will also
As a result the
processes appear to have documentation, but,
in practice, do not. Processes are
inconsistent with inconsistent results.
Nobody recognizes the inconsistencies or
responds to them.
continue, pretty much as before. The whole
thing is, at best, a waste of time. At worst
it diverts efforts from a serious attack on
Rule # 2
Connections with clear
YES/NO signals directly link every customer
This implicit rule
gave rise to kanban, Direct Link and
other lean scheduling. It tells us that
every operation should send its products to
subsequent "customers" directly using
methods and algorithms that are clear and
precise. It precludes separate warehouses
and separate people or departments whose
only function is inventory management.
Rule # 3
Every product and
service travels a single, simple and direct
Toyota's U-shaped work
cells are the ultimate manifestation of this
rule. It means that every piece of
finished product has been through the same
equipment and precisely the same process. It
improves consistency, makes trouble-shooting
easier and simplifies material handling and
Rule # 4
Workers at the lowest
feasible level, guided by a teacher
(Sensei), improve their own work processes
using scientific methods.
Rule #4 ties closely with
Rule #1. It prevents Work Instructions
from becoming moribund memorials rather than
living guides. It enlists the entire
workforce in the improvement (Kaizen)
Rule # 5
tests automatically signal deviations for
every activity, connection and flow path.
This is the concept of
Jidoka or Autonomation. It
prevents products with unacceptable quality
from continuing in the process. The
manifestations of this rule are many,
varied, imaginative and unique to the
process. Examples are detectors for
missing components, automatic gages that
check each part and visual alarms for low
For more information on
THE TOYOTA WAY, please contact:
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