their competitors. It is the foundation for all the other principles... and the
missing ingredient in most companies trying to emulate Toyota.
II. The Right Process Will Produce the Right Results
- Create a continuous process flow to bring problems to the surface.
“Flow” means cutting back to zero the amount of time that any work project is
sitting idle, waiting for someone to work on it. Redesigning work processes to
achieve “flow” typically results in products or projects being completed in one-
tenth the time that was previously required. Flow is most evident in the Toyota
Production System, but it is also evident throughout Toyota in the organiza-
tional culture, which has a focus on value-added flow as an alternative to the
normal stop/start approach to working on projects a little bit at a time. But the
reason to create flow is not just to have material or information moving fast. It is
to link processes and people together so that problems surface right away. Flow
is a key to a true continuous improvement process and to developing people.
- Use “pull” systems to avoid overproduction.
Your customers have extremely demanding service requirements. They want
parts when they want them, in the amount they want, and missed shipments
are unacceptable. So what can you do about this? The obvious answer is to rent
a warehouse and hold lots of inventory so you have the maximum of anything
they might possibly want. Toyota’s experience has proven that to be the wrong
answer. In fact, stocking inventory based on forecasted or even promiseddemand
almost always leads to chaos, firefighting, and running out of the very products
the customer wants. Toyota found a better approach, modeled after the
American supermarket system. Stock relatively small amounts of each product
and restock the supermarket shelf frequently, based on what the customer actu-
ally takes away. The kanbansystem is often viewed as the signature of the Toyota
Production System. But the underlying principles and the systems needed to
make it work effectively are often misunderstood. And the kanbansystem is itself
waste which should be eliminated over time.
- Level out the workload (work like the tortoise, not the hare).
The only way to realistically create a continuous flow is to have some stability
in the workload, or heijunka. If the demand on an organization rises and falls
dramatically, it will force the organization into a reactive mode. Waste will nat-
urally rear its ugly head. Standardization will be impossible. Many companies
believe unevenness in workload is simply the natural order of things created by
an unstable environment. Toyota works to find many clever ways to level the
workload to the degree possible. Spikes and peaks are handled through flexible
workforces brought in from contracting companies and suppliers.
Chapter 1. Background to the Fieldbook 9