Reliability assessment of aerospace electronic equipment

Reliability assessment has been discussed extensively in the commercial aerospace and military avionics industries where, unlike most other industries, it is necessary to have formal, quantitative estimates of the reliability of products prior to the start of production. Until recently, handbook databases and equations were used almost universally for electronic equipment reliability prediction based on failure rates; however, handbook usage is declining and new approaches are needed. Representatives of a large segment of the aerospace industry have worked together to develop an alternative. The Reliability Assessment Program (RAP) is credible, easy to use and holds promise for wide acceptance. RAP does not prescribe a uniform method for all users; instead, it is flexible, encouraging the user to take into account all the unique design, manufacturing and use factors critical to the reliability of the product being assessed. A RAP document is being developed as an industry consensus standard for aerospace electronic equipment manufacturers to use in documenting their reliability assessment processes, including data sources, calculation and analysis methods, results reporting and continuous improvement of the assessment process by comparing assessment results with achieved in-service reliability. RAP is described in this paper, along with current activities to implement it and gain acceptance across the industry.