7. Process Capability

  1. Thomas P. Ryan

Published Online: 18 JUL 2011

DOI: 10.1002/9781118058114.ch7

Statistical Methods for Quality Improvement, Third Edition

Statistical Methods for Quality Improvement, Third Edition

How to Cite

Ryan, T. P. (2011) Process Capability, in Statistical Methods for Quality Improvement, Third Edition, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118058114.ch7

Author Information

  1. Smyrna, Georgia

Publication History

  1. Published Online: 18 JUL 2011
  2. Published Print: 18 JUL 2011

Book Series:

  1. Wiley Series in Probability and Statistics

Book Series Editors:

  1. Walter A. Shewhart and
  2. Samuel S. Wilks

ISBN Information

Print ISBN: 9780470590744

Online ISBN: 9781118058114



  • process capability, in-control process - variables measured, within specification limits;
  • distributional assumption for capability indices - distributional properties, process capability indices;
  • process performance indices - as alternative to process capability indices


This chapter contains sections titled:

  • Data Acquisition for Capability Indices

  • Process Capability Indices

  • Estimating the Parameters in Process Capability Indices

  • Distributional Assumption for Capability Indices

  • Confidence Intervals for Process Capability Indices

  • Asymmetric Bilateral Tolerances

  • Capability Indices That Are a Function of Percent Nonconforming

  • Modified k Index

  • Other Approaches

  • Process Capability Plots

  • Process Capability Indices Versus Process Performance Indices

  • Process Capability Indices with Autocorrelated Data

  • Software for Process Capability Indices

  • Summary

  • References

  • Exercises