130 ◾ A Factory of One
Rather than pass the error to the end of the line—where it will
certainly be more expensive to fix and might be overlooked—
the worker addresses the defect in real time. More importantly,
the worker identifies the origin of the defect and creates a
countermeasure to ensure that the problem never recurs. This
is the root-cause approach to solving problems.
Which long-term system do you want?
Five Whys
One of the classic tools for getting to the root cause of a
problem is the “five-why analysis.” In this method, you ask a
series of “why” questions until you identify the true under-
lying problem. The number five is just a guideline, though;
you might only need three whys or you might need ten. The
point is to get beyond simp