years in the plant working on improvement projects before you even reach novice
status in the Toyota Production System. There is a lot to learn that can only be
learned by doing. Mapping makes people feel like they’re doing lean, but it is
simply drawing pictures. To push an earlier analogy further, if I hand you a blue-
print, it does not mean you can build the house. There are many skills involved.
Creating Flow Step by Step
Value stream mapping gives us a picture of how to put the pieces of the puzzle
together to get a connected value stream. When we do specific point kaizen, we
can reduce changeover time here, set up a cell there, put in a few mistake-proof-
ing devices across the plant, and end up with little islands of improvement. But
the big bang comes from setting up a system where material flows smoothly
across processes based on the takt time—the rate of customer demand. The
operations should be synchronized like a fine symphony orchestra. But how do
we get to this point? Once the future state map is drawn, how should we pro-
ceed to implement it?
The creation of lean processes requires a methodical, step-by-step approach.
The first step prior to setting up one-piece flow is to create a stable process capa-
ble of meeting customer requirements. The creation of flow, and the subsequent
connecting of operations, forces problems to surface, and any abnormalities will
shut down production. It is imperative that all operations achieve a basic level
of consistent capability prior to the establishment of flow. If flow is attempted
before this basic readiness, the result could be catastrophic. Do not aim for per-
fection, since improvement should continue once you have set up good flow.
After one operation has reached this level, a second process is stabilized, and
then the two processes are “connected,” or “linked,” making each process
dependent on the other. This continues over and over until all operations in the
value stream are connected, and flow with minimal stoppages is continuous
from the first operation to the last. The continuous improvement cycle is shown
in Figure 3-3.
This process is typically introduced in a “phased” or “staged” implementa-
tion. Initially each operation in the value stream progresses through the phases
independently. After successfully connecting to other operations, the entire
chain progresses concurrently. With a step-by-step compression of the time
frame representing the customer requirement—weekly schedules become daily,
become hourly, and so on—the process with the greatest weakness (most waste)
will appear.
This repeated loop could be thought of as a spiral of deepening flow as
illustrated in Figure 3-4. Each cycle through the phases results in ever smaller
Chapter 3. Starting the Journey of Waste Reduction 49