A statistical chart used to monitor process stability over time and detect unusual variation.
Control charts help teams distinguish normal process variation from signals that require investigation.
They are a core tool for preventing drift before defects escalate into shipment issues.
How control charts work
Data points are plotted against a center line with upper and lower control limits.
Out-of-control patterns such as runs, trends, or limit breaches indicate special causes that require action.
Operational usage
Teams use control charts on critical process and product characteristics to catch instability early.
When signals appear, supervisors can contain risk quickly and investigate root causes before customer impact.
Key takeaways
- Control charts monitor stability, not just conformance.
- Special-cause signals should trigger investigation and containment.
- Fast data flow improves reaction speed and reduces escapes.