Software) to predict the failure rate of a ceramic capacitor. The failure rate for parts under specific operating conditions can beįigure 1 shows an example using the MIL-HDBK-217 method (in ReliaSoft Provides multi-level quality specifications (expressed as π Q). Many environmental conditions (expressed as π E) ranging from "ground benign" to "cannon launch." The standard also Requires the specific part’s complexity, application stresses, environmentalįactors, etc. Operating conditions will result in failure rates that are different from Since the parts may not operate under the reference conditions, the real Is the failure rate under the reference conditions The failure rateįor a part under the reference conditions is calculated as: Mode and environment (called reference conditions). Part complexity, ambient temperature, various electrical stresses, operation The parts count method assumes typical operating conditions of The parts count method and the other is called the part stress The MIL-HDBK-217 predictive method consists of two parts one is known as Had two revisions: Notice 1 in 1992 and Notice 2 in 1995. The latest version is MIL-HDBK-217F, which was released in 1991 and Is probably the most internationally recognized empirical prediction method,īy far. MIL-HDBK-217 is very well known in military and commercial industries. Some of the available prediction standards and the following sectionsĭescribe two of the most commonly used methods in a bit more detail. Popularity within industry in the past three decades. That have been created for specific applications. There are many different empirical methods The assumption is made that system orĮquipment failure causes are inherently linked to components whose failuresĪre independent of each other. Some parameters in the curve function can be modified by Tend to present good estimates of reliability for similar or slightly Empirical (or Standards Based) Prediction MethodsĮmpirical prediction methods are based on models developedįrom statistical curve fitting of historical failure data, which may haveīeen collected in the field, in-house or from manufacturers. Higher stresses and using statistical models to analyze the data. Relatively large number of samples at their specified operation stresses or Testing methods, which are used to determine reliability by testing a Processes and technologies used in the design. Upon an understanding of the physical properties of the materials, operation Of failure mechanisms, failure modes and stresses. Next, we willĭiscuss physics of failure methods, which are based on root-cause analysis Used for reliability prediction of electronic products. Standards, suchĪs MIL-HDBK-217 and Bellcore/Telcordia, are widely The experiences of engineers and on historical data. Will provide an overview of all three approaches.įirst, we will discuss empirical prediction methods, which are based on (standards based), physics of failure and life testing. Among these approaches, three mainĬategories are often used within government and industry: empirical Prediction of electronic systems and components. Several different approaches have been developed to achieve the reliability Reliability of electronic products requires knowledge of the components, theĭesign, the manufacturing process and the expected operating conditions. To obtain more accurate reliability predictions. Once the prototype of a product is available, lab tests can be utilized Aiding in business decisions such as budget allocation and scheduling.Establishing goals for reliability tests.Providing models for system reliability/availability analysis.Comparing different designs and life-cycle costs.Identifying potential design weaknesses.Reliability goals, such as MTBF, can be reached. Objective of reliability prediction is not limited to predicting whether System before failure data are available for the system. Historically, this term hasīeen used to denote the process of applying mathematical models andĬomponent data for the purpose of estimating the field reliability of a To the concept of reliability prediction. Should be integrated from the very beginning of the design phase. To obtain high product reliability, consideration of reliability issues Higher reliability than competitors is one of the key factors for success. In today's competitive electronic products market, having Software Used: Lambda Predict, Weibull++, ALTA
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