| タイトル | An experimental evaluation of software redundancy as a strategy for improving reliability |
| 著者（英） | Knight, John C.; Kelly, John P. J.; Lee, Larry D.; Eckhardt, Dave E.; Mcallister, David F.; Caglayan, Alper K.; Vouk, Mladen A. |
| 著者所属（英） | Virginia Univ.|California Univ.|North Carolina State Univ.|Old Dominion Univ.|NASA Langley Research Center|Charles River Analytics, Inc. |
| 発行日 | 1991-07-01 |
| 言語 | eng |
| 内容記述 | The 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. |
| NASA分類 | COMPUTER PROGRAMMING AND SOFTWARE |
| レポートNO | 91A52160 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/345791 |
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