learn.howToCalculate
learn.whatIsHeading
Analyzes whether a process can consistently meet specifications. Compares process variation to specification limits.
Formule
Cpk = (specification - mean) ÷ (3 × std dev)
Guide étape par étape
- 1Measure process output (25+ samples)
- 2Calculate standard deviation
- 3Define specification limits
- 4Cpk = (specification - mean) ÷ (3 × std dev)
- 5Cpk >1.33 capable, >1.67 excellent
Exemples résolus
Entrée
±0.1 spec
Résultat
Cpk 0.67
Erreurs courantes à éviter
- ✕Confusing Cp (potential) with Cpk (actual capability)
- ✕Using too few samples or not accounting for stratification
Questions fréquentes
What Cpk indicates capability?
Below 1.0 unable to meet spec; 1.0-1.33 capable with tight control; >1.67 excellent.
What causes low Cpk?
High variation, process drift, poor equipment, untrained operators, or unrealistic specifications.
Prêt à calculer ? Essayez la calculatrice gratuite Process Capability
Essayez-le vous-même →