Process capability (Cp, Cpk, Pp, Ppk)

Required inputs

• Observations — Numeric observations; preserve the row and column structure described above.
• Lower specification limit — Enter the method parameter described above.
• Upper specification limit — Enter the method parameter described above.
• Within-process SD (estimated from rational subgroups) — Enter the method parameter described above.

Review missing values and data coding before running. Sample inputs are synthetic teaching examples.

Implementation

Lifescio formulas and summaries over NumPy arrays. Sample variances use ddof=1; custom formulas are described in the method help.

• numpy 2.2.6: numpy.mean, numpy.std

These are pinned library versions; saved results record the versions actually used at runtime.

Library references

• SciPy statistical methods
• statsmodels models and statistical tests
• scikit-learn clustering
• lifelines survival comparisons