Among the
PCIs, the simplest and widely used index is Cp(Kane, 1986;
Kotz and Johnson, 2002). The 95% confidence limits for Cp
and Cpk were developed by Chou et al. (1990) and Bissell
(1990). Balamurali and Kalyanasundaram (2002) developed
the confidence limits using the bootstrap method for Cp,Cpk
and Cpm.