A method of solving problems on assembly lines by stopping the line at the end of the work cycle - that is, at a fixed position - if a problem has been identified that cannot be solved during the work cycle.
When an operator identifies a problem with parts, tools, material supply, safety conditions and so on, he pulls a cord or presses a button to alert the supervisor. The supervisor assesses the situation and determines if the problem can be resolved before the end of the current work cycle. If the problem can be solved, the supervisor resets the signaling system so the line does not stop. If the problem cannot be fixed within the remaining cycle time, the line is stopped at the end of the work cycle.
The fixed-position stop system was first used by Toyota to solve three problems: (1) employees were very reluctant to pull the "emergency brake" if by doing so they immediately stopped the entire line, (2) unnecessary stopping of the line
for fixing minor problems that could be fixed within one work cycle and (3) if the line was stopped mid-cycle instead of at the end, confusion automatically occurred -- plus quality and safety problems -- because tasks had to be restarted mid-cycle.
The fixed-position stopping system is a jidoka method, which aims to incorporate quality into manual processes on a conveyor belt.