Cpk (Process Capability Index)
Process Capability Index (Cpk) quantifies how consistently a process delivers outputs within the required tolerance. A higher Cpk indicates fewer defects and less rework.
Understanding the calculation
Cpk compares the distance between the process mean and the nearest specification limit to three times the process standard deviation. Values above 1.33 are often considered capable for production.
Using Cpk for decision-making
Quality teams monitor Cpk to decide when processes require adjustment or when tooling should be recalibrated. A declining index can signal drift that needs containment before defects reach customers.
Pairing Cpk with Control limit monitoring offers a complete view of statistical process control.
Cpk dashboards in KaizenQ
KaizenQ aggregates inspection measurements to display capability indices across production lines. Engineers can spot anomalies early and assign follow-up actions within the same workspace.
- Cpk quantifies process capability relative to specification limits.
- Monitoring Cpk trends helps prevent quality escapes.
- Dashboards make it easy to compare capability across suppliers.