Jidoka ◾ 129
Informative Inspections—Reducing Defects
These are designed to discover defects, as opposed to errors, and to give
feedback to the source, which then takes corrective action. Often they entail
the use of statistical tools such as sampling protocols and SPC. Informative
inspections tend to be superior to judgment inspections, but feedback and
countermeasures often lag.
The most effective informative inspections are those that involve self-
checking or successive checking.
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Self-checking means that the opera-
tor checks his or her own work. U-shaped cells support self-checking by
placing the start and end process side by side. In successive checking the
downstream process checks for defects and provides immediate feedback.
Such ch ...