What is Control Limit?
Control Limit
The range where the value usually stays.
What it means
Control limits are the range over which values move when the process runs as usual. It is determined by calculating the value measured by the factory itself.
Even if the value is outside this range, it is not a defect. However, it is a sign that something out of the ordinary has happened, so we look for the reason.
At the pen factory
The line thickness of the refill was usually between 0.48 and 0.52 mm. This is the control limit.
Why it matters
Only by determining what is “normal” can you know what is “different from usual.”
How this differs from Specification Limit
The control limit is the usual range shown by the process itself, and the specification limit is the range of acceptance set by the customer or design.