Reliability analysis and evaluation techniques include reliability analysis techniques, environmental stress screening techniques, reliability test techniques, equipment reliability and life assessment techniques.
1、Reliability analysis techniques
Reliability analysis technique is an important technical measure for product reliability design. Through reliability analysis, we can understand the problems and risks of product design solutions. Through design improvements, we can eliminate potential failure causes in the design stage and achieve the purpose of preventive design. Reliability analysis techniques mainly include failure mode effects and criticality analysis (FMECA analysis), fault tree analysis (FTA analysis), reliability prediction, and reliability modeling.
2、Environmental stress screening techniques
Environmental stress screening is a kind of non-destructive test for 100% inspection of products. By applying a reasonable environmental stress and electrical stress to the product, the potential defects are changed into failures so that they can be found and eliminated.
GRGT can conduct environmental stress screening tests during product development, production and use according to GJB1032-90, GJB451-90, MIL-STD-721C-81, MIL-STD-785B-80. GRGT determines whether the conventional screening or quantitative screening are necessary according to the conditions and determines the screening program according to the characteristics of the different stages and products. It can conduct different stress screening tests for components, devices, connectors or the complete system according to different requirements. The main tests for environmental stress screening are:
Electrical stress screening: Live work test, live and load test;
Temperature stress screening: high temperature, low temperature, high temperature work or low temperature work;
Environmental stress screening: temperature changes;
Mechanical stress screening: shock or vibration;
Other screening: parameter screening, conformity screening.
3、Reliability test techniques
The reliability tests are intend to find various defects in the design, materials and processes of the product, provide information to improve the operation readiness of products, increase the success rate of the task, and reduce the maintenance costs, and confirm whether to meet the specified quantitative reliability requirements. GRGT can conduct reliability compliance tests, reliability acceptance tests, reliability growth tests according to GJB 899A-2009 Reliability Testing for Qualification and Production Acceptance, GJB 1407-2009 Reliability Testing for Growth and other military standards.
4、Reliability assessment techniques
Reliability assessment refers to use the test or use information generated at each stage of the life cycle, give the estimated values of the reliability features under a specific condition with probability statistics method, generally including reliability parameters at a given confidence level, such as the lower estimate of the average time between failures, reliability and failure-free operation time.
Reliability assessment is carried out according to the agreed procedures, methods and the principles of data processing and assessment and project implementation and in conjunction with the actual model. GRGT is qualified in unit reliability assessment and system reliability assessment. Of them, the unit reliability assessment includes the reliability point assessment of various statistical model data and the evaluation of the unilateral and bilateral confidence limits for a given confidence level, for example, binomial distribution, exponential distribution, Weibull distribution, normal distribution, logarithmic normal distribution. System reliability assessment methods include Bayesian small sample method and computer simulation method. Bayesian small sample method is one of the effective methods to solve the problem of insufficient reliability information.