Page 45 - How To Implement Lean Manufacturing

26 Cha pte r T w o

• Waiting. This is simply workers not work-
ing for whatever reason. It could be short-
Point of Clarity Don’t work
term waiting, such as what occurs in an
at getting good at something unbalanced line (see the story of the Bravo
which should not be done at all! Line in Chap. 15), or longer waits, such as
for stock outs or machinery failure.
• Transportation. This is the waste of moving parts around. It occurs between
processing steps, between processing lines, and happens when product is shipped
to the customer.
• Overprocessing. This is the waste of processing a product beyond what the
customer wants. Engineers who make specifications that are beyond the needs
of the customer often create this waste in the design stage. Choosing poor
processing equipment or inefficient processing equipment increase this waste also.
• Movement. This is the unnecessary movement of people—such as operators and
mechanics walking around, looking for tools or materials. All too often, this is
frequently overlooked as a waste. After all, the people are active; they are moving;
they look busy. The criterion is not whether
they are moving, it is: Are they adding value
Point of Clarity The TPS is a or not? I can‘t think of any example of people
batch destruction technique. movement that is value added. Work design
and workstation design is a key factor here.
• Inventory. This is the classic waste. All inventories are waste unless the inventory
translates directly into sales. It makes no difference whether the inventory is raw
materials, WIP, or finished goods. It is waste if it does not directly protect sales.
• Making defective parts. This waste is usually called scrap. But the phrase Ohno
uses, “making defective parts” is classic Ohno. Most people use the term “scrap,”
so they view the defective part as waste. Ohno moves far beyond this. He not only
categorizes the part as scrap, but the effort and materials to make it. Ohno was a
natural process thinker. In this case, he not only lamented the loss of a production
unit but the fact that people spent valuable time, effort, and energy to make the
unit—all of which was lost, not just the production unit.

The TPS Is Not a Complete Manufacturing System
The TPS is not a complete manufacturing system. In fact, it is only a part of a manufac-
turing system. To better understand what part of a manufacturing system it is, or rather
what it is not, we need to return to Ohno’s book for a moment. While discussing flow as
the basic condition, he writes:
These two sentences are so simple that their sig-
nificance is missed by almost everyone. However,
“After World War II, our main the implication to these two sentences, especially
concern was how to produce high to those wishing to undertake a TPS initiative, must
quality goods and we helped the be thoroughly understood. For example, let me para-
cooperating firms in this area. phrase it a bit:
After 1955, however, the ques-
tion became how to make the “From the end of WWII until 1955, we had focused
”
exact quantity needed. our attention on improving the quality of our goods.
T. Ohno By 1955, we thoroughly knew how to provide quality
to our customers. We could discuss the key quality