JSM 2012 Home

JSM 2012 Online Program

The views expressed here are those of the individual authors and not necessarily those of the JSM sponsors, their officers, or their staff.

Online Program Home

Abstract Details

Activity Number: 239
Type: Contributed
Date/Time: Monday, July 30, 2012 : 2:00 PM to 3:50 PM
Sponsor: Quality and Productivity Section
Abstract - #305385
Title: Conditional Confidence Intervals of the Process Capability Index Cpk
Author(s): Chien-Pai Han*+ and Jianchun Zhang
Companies: The University of Texas and The University of Texas at Arlington
Address: P.O. Box 19408, Arlington, TX, 76019-0001, United States
Keywords: Preliminary test ; conditional confidence interval ; process capability index ; length of interval ; coverage probability

The process capability index Cpk involves the process mean µ and the process standard deviation s. When µ and s are unknown we can estimate them by a random sample. When we have uncertain prior information about their values, we may check the uncertain prior information by preliminary tests. Then we can construct a conditional confidence interval of the process capability index Cpk following rejection of the preliminary tests. In this paper, we adopt two tests for testing µ and s separately and sequentially, instead of testing µ and s jointly. Conditional confidence intervals of Cpk following different results of the two tests are provided. For the case that both of the two null hypotheses are rejected, we construct the confidence interval of Cpk for which the two parameters µ and s are all unknown. An extension of the general method for finding a confidence interval of an unknown quant

The address information is for the authors that have a + after their name.
Authors who are presenting talks have a * after their name.

Back to the full JSM 2012 program

2012 JSM Online Program Home

For information, contact jsm@amstat.org or phone (888) 231-3473.

If you have questions about the Continuing Education program, please contact the Education Department.