Each management level should think of managing in terms of or her”zone”. In an
ideal world, it might be possible to produce with no defects,but unfortunately accidental defects can occur everywhere at any time in the real world.
However ,even if we might make defects , we can stop them before they go to
the next process.We can stop them before they go to the next process. We call
this “Zone Control”. As an example ,automatic line stop is one of the methods for
In traditional mass production ,a specialized inspector outside of the production process checked for quality.
Lean zine control
Lean producers assign quality assurance to operators and employ Erro-Proofing devices within each production process in order to detect the problems at the sources.