Resource Library/Process Control and Measurement/Process Capability (Cp/Cpk) Calculator
Process Capability (Cp/Cpk) Calculator
Paste your readings and get Cp, Cpk, Pp and Ppk with the published constants, a confidence bound, the expected parts out of specification, a stability check and a picture of the spread.
- Excel
- fillable PDF
- Worked example
- Your logo on it
- Aegis Insights
Page 1 of the PDF. Every resource includes a fully worked example.
The problem it solves
Capability numbers end up in PPAP and first article packages, corrective action closures and customer scorecards, and they are often wrong in quiet ways: the within and overall spreads mixed up, a study on an unstable process, a gauge nobody studied, or 30 readings quoted as if they were 3,000. This calculator works out the indices the standard way, shows both spreads side by side, checks stability, puts a confidence bound on the result, and records the decision with its reasons.
Who uses it
Quality and manufacturing engineers; anyone who has to quote or check a Cpk.
When
When a customer asks for capability on a key characteristic; to verify a corrective action; before reducing inspection; and on a regular cycle for characteristics on a control chart.
Free to use, change and copy, in your own organization or with your clients; add your own logo, keep the Aegis credit. Clause references: 9.1.1, 9.1.3 (with 8.5.1 and 7.1.5) (numbers only; use your own licensed copy of the standard).
A management aid, not certification or a registrar audit. Using it does not by itself show conformity to AS9100D or any other standard.
How to put it to work
Chapters of our free guides that use this tool.
- The kit and how the tools connectThe Calibration Control Kit Handbook, chapter 2
- The kit and how the tools connectThe FAI and Production Readiness Kit Handbook, chapter 2
- Proving fitness: measurement system analysis (E03, E04)The Calibration Control Kit Handbook, chapter 10
- Inspection planning and key characteristics (E11, D16, E07)The FAI and Production Readiness Kit Handbook, chapter 7
- Records that hold upThe Calibration Control Kit Handbook, chapter 13
- After approval: into steady productionThe FAI and Production Readiness Kit Handbook, chapter 14
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These tools help you run the work by hand. When you want the whole picture of your quality system from the records you already keep, that's what the AeroAssure Audit Defense Pack and the IA9100 Transition Gap Analysis do.