Definition:Control Chart
Definition
A control chart is a graph used in quality control to indicate whether or not a property of a mass-produced item falls within acceptable limits.
Hence it can indicate whether there is some defect in the manufacturing process.
A sample is taken at regular intervals from the production line and the property in quesyion is measured.
This is then plotted on the control chart and checked against the target line and control lines.
If the plot is outside the control lines, there is a need to check that the process is working correctly.
Target Line
The target line in a control chart is a straight line indicating the ideal value of the property being measured.
Control Line
A control line in a control chart is one of a number (usually $2$) of straight lines a predetermined distance away from the target line, between which the measurements of the property being measured are expected to lie.
Also see
- Results about control charts can be found here.
Sources
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): control chart
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): control chart