Journal of Probability and Statistics
Volume 2012 (2012), Article ID 819730, 15 pages
Research Article

Bayesian Estimation of Generalized Process Capability Indices

Department of Statistics, Visva-Bharati University, Santiniketan 731 235, India

Received 14 May 2011; Revised 6 December 2011; Accepted 13 December 2011

Academic Editor: Shein-chung Chow

Copyright © 2012 Sudhansu S. Maiti and Mahendra Saha. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Process capability indices (PCIs) aim to quantify the capability of a process of quality characteristic (X) to meet some specifications that are related to a measurable characteristic of its produced items. One such quality characteristic is life time of items. The specifications are determined through the lower specification limit (L), the upper specification limit (U), and the target value (T). Maiti et al. (2010) have proposed a generalized process capability index that is the ratio of proportion of specification conformance to proportion of desired conformance. Bayesian estimation of the index has been considered under squared error loss function. Normal, exponential (nonnormal), and Poisson (discrete) processes have been taken into account. Bayes estimates of the index have been compared with the frequentist counterparts. Data sets have been analyzed.