Cover: Estimates of Reliability During the Test and Evaluation Stage

Estimates of Reliability During the Test and Evaluation Stage

Some Methodological Observations

Published 1985

by Jack Zwanziger


Download eBook for Free

FormatFile SizeNotes
PDF file 0.9 MB

Use Adobe Acrobat Reader version 10 or higher for the best experience.


Purchase Print Copy

 Format Price
Add to Cart Paperback39 pages $20.00

Within the acquisition process, reliability testing is one of the methods the military has used to maintain control of the reliability characteristics of a system being developed. Reliability testing has multiple objectives, including (1) determining compliance with contractual requirements; (2) identifying deficiencies in the system; (3) providing reliability measures for use in operation planning; and (4) measuring the readiness of the system for production and operational use. Applying the statistical techniques generally used, this paper illustrates the statistical risk facing both the military purchaser and the contractor from testing less, and conversely, the gains in statistical confidence from testing more. It considers two basically different kinds of reliability: (1) binomial processes, where "success" or "failure" are defined and testing is required to estimate the probability of their occurrence and (2) time-to-failure reliability, where "failure" is defined and the times when failures occur are recorded. The author concludes that both these approaches are likely to require some increase in the size of test programs.

This report is part of the RAND paper series. The paper was a product of RAND from 1948 to 2003 that captured speeches, memorials, and derivative research, usually prepared on authors' own time and meant to be the scholarly or scientific contribution of individual authors to their professional fields. Papers were less formal than reports and did not require rigorous peer review.

This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit

RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.