Page 62 - Lean six sigma demystified

Chapter 2 Lean Demy S tifie D 41

the financial crisis of 2008–2009. This shows, however, how easy it is for a
leadership team focused on growth and profits to cut corners on quality and
injure the company’s reputation. Toyota, long renowned for quality, will quickly
solve its safety problems and return to preeminence.
At its heart, Lean is about speed and the relationship between steps in a
process. It’s about eliminating non-value-added elements from the process. It’s
about shrinking batch sizes down to create a one-piece flow.
Lean thinking originated at Toyota with the TPS. Sakichi Toyoda formu-
lated the original ideas in the 1920s and 1930s. Taiichi Ohno began to imple-
ment these ideas in the 1940s but only made the leap to full implementation
in the 1950s.
The two pillars of the Toyota Production System are

1. Just in time (JIT). The right parts reach the assembly line when needed in
the amount needed. Taiichi Ohno admits that, in the beginning, JIT
“seemed to contain an element of fantasy.”
2. Autonomation. Automation with the human touch, meaning that a machine
will stop on its own if it detects an error allowing a single worker to
handle multiple machines. Toyoda’s automated weaving looms would
stop automatically if the thread broke. The same is true of their automo-
tive production lines.

I tried thinking about the transfer of materials in the reverse direction: a later process
goes to an earlier process to pick up only the right part in the quantity needed at the
exact time needed.
—Taiichi Ohno

Some of the principles of Lean (e.g., pull and Kanban) came from a surpris-
ing source: U.S. supermarkets where small quantities of inventory are replen-
ished as customers pull them off the shelves. Shelves are restocked as they
become depleted. In a pull system, the preceding process must always do what
the subsequent process tells it. The visual ability to see low stock and replenish
it became known as the kanban (aka card) system. Supermarkets are the essence
of a kanban inventory and pull system. (How can you create a supermarket-
style inventory system?)
A kanban is a piece of paper in a clear envelope attached to materials or
products. It contains information about production quantity, source, destina-
tion, and transfer. Kanban lets products carry their own information.