The Prius That Shook.. - VFAQ Prius Site

He targeted processes that would be subject to lint exposure,
and tried to improve them.
However, the line workers who were used to the production
method for general use batteries were confused. Fujii took
his time to explain and tried to change the practices of
the workers, who still failed to understand why this procedure
was necessary.
Matsushita had been manufacturing only car batteries,
dry cell batteries, and general use batteries for PCs and electric
tools. For such uses, the aging process was enough to remove
the defective ones. A company that made batteries for decades
would not think of reducing the defective rate to zero in the
manufacturing process.
Some time later, test production for batteries began,
and Tsujido Plant began producing them. As expected, a
battery problem came up. All of the 240 cells were returned
to the plant, and the workers measured each cell with a tester.
They found one defective cell. When they disassembled it,
there was a small piece of lint inside. As these instances were
reported frequently, each worker began to realize the
significance of one cell causing the car to fail.
"This is a serious issue. We can't meet the stringent
requirements if we don't do what we should." Workers
were now voluntarily cleaning and improving the production
line. The difficulty of connecting 240 cells in series and
Toyota-style quality control concept were literally a "culture
shock" to the workers at Matsushita
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