|
|
| Quick Changeover / SMED: An OverviewDecember 31, 2003 Recently, I was reviewing the incredible statistics that were produced by the recipients of the 2003 Shingo Prize for Manufacturing Excellence. Despite encompassing a variety of industries, all of the winning organizations demonstrated the same results in their continuing efforts to achieve World Class status. Just some of their accomplishments were:
The Shingo Prize, which Business Week calls “The Nobel Prize of Manufacturing,” was established in 1988 to recognize North American companies that achieve World Class Status. The prize was named after Dr. Shigeo Shingo, the Japanese Industrial Engineer often referred to as an “engineering genius.” Dr. Shingo revolutionized manufacturing by creating many of the practices that make up the Toyota Production System, now referred to as Lean Manufacturing. While Dr. Shingo’s accomplishments are numerous and his system well proven, organizations often struggle to comprehend and implement his system. In the process of developing JIT while
working for Toyota in 1962, Dr. Shingo was able to reduce the set-up time for a
1000-ton press from four hours to one and a half hours.
Shortly thereafter he was asked by management to further reduce the
set-up time to three minutes. He developed an approach that was in complete
contrast to traditional manufacturing procedures. In a few short months, he
accomplished his goal, reducing the time from hours to a single digit.
Hence, Single Minute Exchange of Dies or SMED was born. Even more
remarkable, no capital
spending was required. Based
on his vast experience, this method to analyze the changeover process enabled
the people performing the changeover to find out why the changeover took so
long, and how this time can be reduced. In many cases, his system can reduce
changeover and setup times to less than ten minutes. In
modern times with rapidly
increasing diversity and smaller batch sizes, using setup time reduction to
improve cash flow and profitability is becoming critical to the survival of
manufacturers. Many companies spend more than 20% of their planned production
time on changeovers.
The basic concept of SMED is to reduce machine setup time, which directly
results in smaller batch sizes for parts, allowing the manufacturer to produce
only what is demanded by the customer. A smaller batch size also translates to
lower WIP inventory holding costs in the form of:
Dr. Shingo’s SMED System consists of the following 4 phases:
The
method's strength is its systematic analysis of what is actually done and how
time is spent during the changeover activity. Dr.
Shingo’s approach was to isolate and identify the setup time as two entities:
internal setup time and external setup time. His simple approach to achieving a
quick setup and changeover of the dies consists of the following steps:
Internal operations are those that are done while the machine (or line) is shut down. External operations are those that can be done while the machine is running. Externalizing operations reduces downtime, which is the major cost associated with setup or changeover. (It is not labor, as some might assume.) Streamlining involves eliminating unnecessary operations as a first step followed by instituting process changes to shorten or eliminate other operations. Shingo’s classic "A Revolution in Manufacturing: The SMED system" should be required reading for anyone involved in manufacturing. In the book, Dr. Shingo describes how he developed SMED and how the reader can apply the same techniques to any industrial process. In his book, Shingo gives many practical illustrations of application of the SMED concept to a variety of different processes. There are many photos and sketches that supplement the text. One
common objection to SMED is its metalworking industry focus. It is true that Dr.
Shingo's experience was in such industries, and the illustrations in the book
are of machines like stamping presses, lathes, and other heavy metal-working
equipment. But the basic principles behind SMED are universal, and the system
has been used to successfully reduce setup and changeover times in many types of
industries. A
good analogy to the concept of SMED or quick changeover is changing an
automobile tire. Changing a tire typically takes between seven and fifteen
minutes. Just list the number of operations involved. Now, why can a pit crew
change four tires in a few seconds during an auto race? Some of the
reasons are:
The
reason they have all of these things in place should be the same reason any
manufacturing organization should implement a SMED or Quick changeover program:
they are in a fierce competition! In the Lean toolbox, SMED / Quick
Changeover is one of the most rewarding programs that a manufacturing
organization can utilize. The
benefits include lower inventories, faster deliveries, and improved efficiency.
Above all, you will see an increase in the morale, pride, and overall
attitude of your employees. Whether
your changeovers involve setting up a machine or are less traditional, SMED can
reduce your changeover time. And
this will ultimately result in more productivity, satisfied customers, and
increased profits. Click here to subscribe to our free e-newsletter Learning to Lean and receive three articles like this one each month. About
the Author David McBride is co-founder of EMS Consulting Group (http://www.emsstrategies.com), a Carlsbad, CA based engineering and management consulting firm. David has a BS in Mechanical Engineering from Ohio State University. He has a successful track record in the development and implementation of FMEA and Design for Manufacturability programs at several organizations and has greatly reduced Manufacturing costs through the utilization of Lean Manufacturing, Kaizen Events, and Manufacturing System Analysis. He has also been highly successful at developing and executing New Product Introduction processes, and Staffing and Capital Equipment Plans. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
Send mail to
webmaster@emsstrategies.com with
questions or comments about this web site.
|
