Automatic Line Stop

Ensuring that a production process stops whenever a problem or defect occurs.

For an automated line this usually involves the installation of sensors and switches that automatically stop the line when an abnormality is detected. For a manual line a fixed-position stop system often is installed. This permits operators to pull an overhead cord or push a button that stops the process at the end of a work cycle if the problem encountered cannot be fixed during the cycle.

These examples illustrate the lean principle of jidoka, which prevents defects from going to the next phase of production and avoids the waste of making a series of defective items. Mass producers, by contrast, will try to keep lines running to achieve high equipment utilization, even when known defects occur repetitively and require rework at the end of the process.