Page 63 - The Toyota Way Fieldbook

Chapter 3. Starting the Journey of Waste Reduction 41

vigilant about auditing, going to see, and improving further. Once we
have achieved much of our future state map, it’s time to develop another
current state map on where we are now, and then develop yet another
future state map. You should choose time periods for the mapping hori-
zon that encourage concrete action, for example, looking six months to
one year into the future is more realistic than five years into the future.

TRAP
Fixing Problems in the Current Value Stream
The real benefit of value stream mapping is that it gets us away
from isolated point kaizen and we can build toward a true system
based on the flow of materials and information across the entire
value stream. We teach this methodology a lot and can recall
numerous cases in which we followed up with a student and heard
the following:
That value stream mapping is great. I developed a map of one of
our processes we wanted to improve, and it revealed all sorts of
waste. We did a couple of kaizen workshops, and the improve-
ments were remarkable—we took out three people, we reduced
inventory by 80 percent, and freed up half the floor space.
We ask: “What do you mean you developed a map of a
process? Didn’t you develop a current and future state map of the
entire value stream?”
Answer: “We did not get that far. There was so much waste
in our stamping department we started there and developed a cur-
rent state map to show the waste and went to work right away.
At some point we will get to the future state.”
In other words, value stream mapping is being subverted as
a tool for point kaizen. You will get a fraction of the benefit by
improving isolated processes.

Benefits of the Value Stream
Mapping Approach

Value stream mapping is more than a neat tool to draw pictures that highlight
waste, though that is certainly valuable. It helps us see linked chains of processes
and to envision future lean value streams. Underlying value stream mapping is
a philosophy of how to approach improvement. The philosophy is that we need
to straighten out the overall flow of the value stream before we deep-dive into