Determining the lifetime of CD‐RWs using efficient sampling on a production line

This work derives the intermittent batch size and sample size for product life testing on a production line. The sequential probability ratio test was adopted to determine the sample size, $n$ , and the expected number of samples (ENS). An inverse chi‐square approximation was used to determine the relationship between the degree of freedom, $m-1$ , and the estimated range of $\sigma^2$ $(ER\,\sigma^2)$ at various $(1-\alpha)$ levels of confidence. Consequently, ENS and $m$ were used to determine the intermittent batch size, $l$ . Finally, rewritable compact disks (CD‐RWs) underwent testing to demonstrate the feasibility and effectiveness of the proposed efficient sampling approach. Copyright © 2003 John Wiley & Sons, Ltd.