Accession Number:

AD0657676

Title:

UNBIASED ESTIMATES OF RELIABILITY WHEN TESTING AT ONLY ONE EXTREME STRESS LEVEL

Descriptive Note:

Corporate Author:

PICATINNY ARSENAL DOVER NJ QUALITY ASSURANCE DIV

Personal Author(s):

Report Date:

1963-12-01

Pagination or Media Count:

27.0

Abstract:

Based on the stress-strength concept of reliability for one-shot items, it is assumed that an item cannot fail until the stress equals or exceeds the strength. From this premise and the following additional assumptions, methods are given for calculating unbiased estimates of nontime dependent reliability 1 The relation between the stress and strength standard deviations are known approximately. 2 A single stress level is applied during testing at approximately three standard deviations from the average stress level. 3 The stress and strength distributions are normal. Calculations are included to show the effect of errors in the assumptions concerning the standard deviations, applied stress level, and rounding-off errors. This approach further reduces the sample size required to demonstrate high non-time dependent reliability in laboratory testing. It has the added advantage of obtaining unbiased estimates of reliability with the simplest of testing methods.

Subject Categories:

  • Manufacturing and Industrial Engineering and Control of Production Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE