Page 159 - How To Implement Lean Manufacturing

How to Implement Lean—The Pr escription for the Lean Pr oject 137

popular, it usually is an inferior technique to one-value-stream-at-a-time implemen-
tation. The “clean sweep” has a couple of merits that I will discuss in a minute.
However, there are at least four very large reasons to implement one value stream at
a time.
• The initial learning curve is very steep, and no matter how well prepared you
are, there are many unforeseen results. Sometimes they are positive results,
other times negative, but it is best to experience these issues on a smaller scale
and learn from them. This learning from the first line is invaluable in executing
the conversion on the subsequent lines.
• There is the matter of resources … Specifically trained eyes and ears to evaluate
implementation, evaluate progress, and assess problems on the value streams
being converted. No one has a plethora of such people and they are invaluable.
These few people can move from line to line with the implementation and
provide expert advice and training so the gains may be sustained.
• Each change has an effect on subsequent and past changes. It is not uncommon
to Lean out Line A and then move on to Line B for its implementation and then
find some aspect of Line B implementation that has an unexpected effect on
Line A. Sometimes the effect is a positive one, other times it is detrimental, but
either way this approach allows you to better understand these effects so they
may be exploited more fully on all lines .
• I have seen a number of line-by-line efforts progress quite nicely, but all the
global implementation efforts I have seen have struggled to meet their objectives.
A common postmortem comment on a global implementation effort is “In
hindsight, we should have done this one value stream at a time.”
There may be a few cases where plantwide implementation is the best choice. I can
think of two.
• In a few cases I have seen where the customer has decreed that they will only
work with facilities that are Lean, top to bottom.
• The second case is rare but there are some operations where the manufacturing
is trivial compared to the overall operation. Packaging is one such case I have
encountered. In this instance, 19 different products were packaged and shipped
to different countries. Hence, the packages were labeled in many different
languages. The net effect was that there were over 400 individual part numbers.
The manufacturing was not complicated. Rather the complications, and hence
the variation, and hence the waste, was in the interaction with the storehouses.
First, there were the issues of pickup, delivery, and movement of raw materials
from the raw materials storehouse to the production lines. Second was the
handling of the over 400 part numbers on the floor and in the finished goods
warehouse. In this case, the handling of the storehouses was the key issue and
the implementation had to be done globally.

In the absence of these two items, I can find no reasons more compelling than the
four mentioned earlier: learning curves, resources, lessons learned, and historical suc-
cess. Consequently, we have found it usually the best choice to implement one value
stream at a time.