70 ◾ Removing the Barriers to Efﬁcient Manufacturing
assessment of your operation. The main question is what it is costing you in
time, labor, materials, waste, and inventory size to make a product change-
over. And, after the changeover, how long does it take after startup to be
making ﬁrst-class quality product again?
Just like the Japanese, you will also need a vision. So, here is one based
on Point 9 of our Model Vision. The ideal changeover would be instanta-
neous: You push a button, and one minute later, instead of making one
product, you are now making a different product. And, the new product is
immediately good quality. Since this is a common dream among manufac-
turers, they invented a new term: one touch exchange of die (OTED). The
vision for changeover under OTED is 100 seconds or less. If this is not a real-
istic vision for your facility, you will need to develop one that is—aim high.
In the context of producing multiple products on a single production line,
there are some steps associated with a changeover that would appear to be
universal and somewhat self-evident:
1. After shutting down for a changeover, the process must be rendered
safe for people to enter and work on it.
2. The process should be cleaned.
3. Machine settings have to be changed.
4. Some components of the process may have to be replaced (just like the
5. Some raw materials and operating supplies have to be replaced.
6. After initial startup, additional product sampling is needed to ensure the
transition is successful.
7. Machine settings may have to be tweaked before process centerlines
We analyze each of these in detail.
Step 1: Render the Process Safe
While you would like for your employees to be able to function with the
efﬁciency of a NASCAR pit crew, they have to be able to perform their tasks