Evaluation of Environmental Profiles for Reliability Demonstration
Abstract
This report describes the effort during the first 12 months of an 18- month study to determine the adequacy of the environmental profiles of MIL-STD- 781, 'Reliability Tests: Exponential Distribution,' and provide recommendations for their improvement. The environmental and failure history of a sample of 95 avionic WRAs served as the vehicle for this evaluation. Environmental data during demonstration testing and actual field exposure for each WRA was collected, analyzed, and compared. Test failure history and field failure experience have been reviewed and reliability measures for each have been determined. New reliability predictions is accordance with the coordination copy of MIL-HDBK-217B have been performed. Preliminary comparisons of lab-field reliability differences with environmental differences indicate that temperature rate of change, vibration method, and the length of exposure to vibration during testing are significant factors. It was also found that groundrules and failure scoring criteria have a strong impact on reliability differences.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1974
- Accession Number
- ADB000490
Entities
People
- Allan Dantowitz
- George Hirschberger
Organizations
- Grumman