Evaluation of Environmental Profiles for Reliability Demonstration
Abstract
This report describes the results of a 19-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 weapons replaceable assemblies (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 were reviewed and reliability measures for each determined. Comparisons of lab-field reliability differences with environmental differences indicated that: insufficient thermal cycling; inadequate vibration testing in terms of level, duration and frequency; and lack of moisture exposures were deficiencies in the current environmental profiles. Recommended profiles which would eliminate these weaknesses are presented. In addition, the need for consistent ground rules, failure scoring criteria, and a strong end-item burn-in test are described.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1975
- Accession Number
- ADB007946
Entities
People
- Allan Dantowitz
- George Hirschberger
Organizations
- Grumman