Decoding the DNA of
the Toyota Production
by Steven Spear and H. Kent Bowen
Included with this full-text
Harvard Business Review
The Idea in Brief—the core idea
The Idea in Practice—putting the idea to work
Decoding the DNA of the Toyota Production System
A list of related materials, with annotations to guide further exploration of the article’s ideas and applications
The Toyota story has been
intensively researched and
yet what really happens inside
the company remains a
mystery. Here’s new insight
into the unspoken rules that
give Toyota its competitive
Decoding the DNA of the Toyota Production
The Idea in Brief The Idea in Practice
COPYRIGHT © 2006 HARVARD BUSINESS SCHOOL PUBLISHING CORPORATION. ALL RIGHTS RESERVED. Toyota’s renowned production system (TPS)
has long demonstrated the competitive advantage
of continuous process improvement.
And companies in a wide range of
industries—aerospace, metals processing,
consumer products—have tried to imitate
TPS. Yet most fail.
Why? Managers adopt TPS’s obvious practices,
without applying the four unwritten
rules that make TPS successful. Like strands
of DNA, these rules govern how people
carry out their jobs, how they interact with
each other, how products and services flow,
and how people identify and address process
The rules rigidly specify how every activity—
from the shop floor to the executive suite,
from installing seat bolts to reconfiguring a
manufacturing plant—should be performed.
Deviations from the specifications
become instantly visible, prompting people
to respond immediately with real-time experiments
to eradicate problems in their
own work. Result? A disciplined yet flexible
community of scientists
who continually push Toyota closer to its
zero-defects, just-in-time, no-waste ideal.
Mastering TPS’s four rules takes time. But by
dedicating yourself to the process, you
stand a better chance of replicating Toyota’s
DNA—and its performance.
TPS’s four rules:
All work is highly specified in its content,
sequence, timing, and outcome.
Employees follow a well-defined sequence of
steps for a particular job. This specificity enables
people to see and address deviations
immediately—encouraging continual learning
Installing the right-front seat in a Camry requires
seven tasks performed in a specific
sequence over 55 seconds. If a worker finds
himself doing task 6 before task 4 or falling
behind schedule, he and his supervisor
correct the problem promptly. Then they
determine whether to change the task
specifications or retrain the worker to prevent
Each worker knows who provides what to
him, and when.
Workers needing parts submit cards specifying
part number, quantity, and required destination.
Suppliers must respond to materials
requests within specified periods of time.
Workers encountering a problem ask for help
immediately. Designated assistants must respond
at once and resolve the problem within
the worker’s cycle time (e.g., the 55 seconds it
takes to install a front seat).
Failure to fulfill these specifications signals a
search for potential causes—such as ambiguous
requests from colleagues or an overwhelmed
assistant. Once the cause is identified, it’s resolved
rather than kept hidden.
Every product and service flows along a
simple, specified path.
Goods and services don’t flow to the next
available person or machine—but to a
person or machine.
If workers at an auto parts supplier find
themselves waiting to send a product to
the next designated machine they conclude
that their demand on the next machine
doesn’t match their expectations.
They revisit the organization of their production
line to determine why the machine
was not available, and...