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An experimental evaluation of software redundancy as a strategy for improving reliabilityThe strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failires. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with the estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certifications processes, and operational evaluation are given together with an analysis of the twenty versions.
Document ID
19910067537
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Eckhardt, Dave E.
(NASA Langley Research Center Hampton, VA, United States)
Caglayan, Alper K.
(Charles River Analytics, Inc. Cambridge, MA, United States)
Knight, John C.
(Virginia, University Charlottesville, United States)
Lee, Larry D.
(Old Dominion University Norfolk, VA, United States)
Mcallister, David F.
(NASA Langley Research Center Hampton, VA, United States)
Vouk, Mladen A.
(North Carolina State University Raleigh, United States)
Kelly, John P. J.
(California, University Santa Barbara, United States)
Date Acquired
August 14, 2013
Publication Date
July 1, 1991
Publication Information
Publication: IEEE Transactions on Software Engineering
Volume: 17
ISSN: 0098-5589
Subject Category
Computer Programming And Software
Accession Number
91A52160
Funding Number(s)
CONTRACT_GRANT: NAS1-17864
CONTRACT_GRANT: NAS1-17705
CONTRACT_GRANT: NAG1-782
CONTRACT_GRANT: NAG1-744
CONTRACT_GRANT: NAG1-667
Distribution Limits
Public
Copyright
Other

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