DocumentCode :
1349857
Title :
Optimum Simple Step-Stress Plans for Accelerated Life Testing
Author :
Miller, Robert ; Nelson, Wayne
Author_Institution :
General Electric Co., Schenectady; MD: K60; GE Aircraft Engine Bus.; Evendale, OH 45215 USA.
Issue :
1
fYear :
1983
fDate :
4/1/1983 12:00:00 AM
Firstpage :
59
Lastpage :
65
Abstract :
This paper presents optimum plans for simple (two stresses) step-stress tests where all units are run to failure. Such plans minimize the asymptotic variance of the maximum likelihood estimator (MLE) of the mean life at a design stress. The life-test model consists of: 1) an exponential life distribution with 2) a mean that is a log-linear function of stress, and 3) a cumulative exposure model for the effect of changing stress. Two types of simple step-stress tests are considered: 1) a time-step test and 2) a failure-step test. A time-step test runs a specified time at the first stress, whereas, a failure-step test runs until a specified proportion of units fail at the first stress. New results include: 1) the optimum time at the first stress for time-step test and 2) the optimum proportion failing at the low stress for a failure-step test, and 3) the asymptotic variance of these optimum tests. Both the optimum time-step and failure-step tests have the same asymptotic variance as the corresponding optimum constant-stress test. Thus step-stress tests yield the same amount of information as constant-stress tests.
Keywords :
Costs; Least squares approximation; Life estimation; Life testing; Maximum likelihood estimation; Parameter estimation; Statistical analysis; Statistical distributions; Stress; Temperature; Accelerated test; Constant-stress test; Exponential life distribution; Maximum likelihood estimation; Step-stress;
fLanguage :
English
Journal_Title :
Reliability, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9529
Type :
jour
DOI :
10.1109/TR.1983.5221475
Filename :
5221475
Link To Document :
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