Page 196 - How To Implement Lean Manufacturing

174 Cha pte r T e n

Reduce Raw Materials Variation
Often the incoming raw materials have significant variation and this is a problem of
varying degree to everyone. However, most manufacturing firms work with the suppli-
er’s at the process level to improve their processes. They use tools such as 8Ds, Supplier
Certification Programs, and some of the most forward-looking producers have good
Supplier Support organizations. Supplier development was a key tool used by Ohno to
improve his manufacturing system, but he really did not implement this until nearly
20 years after he began his quest for quantity control. Very likely, this will not be a large
issue in your facility for a few years. When it is a priority, luckily, there are a series of
good books on supply chain management, so we will not go into detail here on this
topic.

Simplify the Process
The second most powerful technique is to simplify the process. Most often, the effort is
focused on reducing human interaction. Frequently, this means you will use robotics or
other types of automation. Often, and it is especially true for a tier-1 automobile sup-
plier, this type of simplification is not practical. First, there is the cost issue of the capital
improvements, and beyond that suppliers are required to jump through a whole series
of hoops that tend to discourage these type of improvements. These hoops, known as
process validation, which are mandated by the typical automobile customer, are so
costly and time consuming that even if the change is warranted, it is often not done due
to the rigors involved. In addition, these changes also open the door for the topic of price
reductions. All in all, process simplifications of any magnitude, such as converting
manual operations to robotics, are not done very often.

Poka-Yokes
Poka-yokes (see Chap. 4) are powerful tools and should be fully exploited before other
procedural changes are implemented. I find it curious that poka-yoke technology is not
used more often. I attribute this underutilization to the low levels of imagination
demanded of most manufacturing support engineers. It does not help that I find very
little in-house training being done with poka-yoke technology, although there are several
good references in the literature. Other than a little periodic maintenance required of
most poka-yokes, I see very little justification for their underutilization. The beauty of poka-
yokes is in their simplicity and effectiveness. We can give numerous examples of poka-
yokes that saved $10,000 per dollar invested. That kind of investment is hard to beat.

Standardize the Process Procedures
Unfortunately, the most common type of improvement comes about by improving pro-
cess procedures. What this generally entails is an attempt to reduce variation through
the use of better work descriptions. But in the end we still rely on the human element to
perform well. I used the word “unfortunately” in the first sentence for two reasons.

• First, the human element is often the greatest source of variation and we are
simply trying to do it better, not really differently.
• Second, it is unfortunate because, often times, even with the most imaginative
engineers and managers, that is the best we can do. In fact, this is the most
typical approach taken in the manufacturing world to reduce variation.