HDBK 217 Plus

HDBK 217 PLUS Reliability Prediction Methodology

The 217 Plus prediction module incorporates the component failure rate prediction models developed by the RIAC (Reliability Information Analysis Center). The 217 Plus is updated to develop a replacement prediction methodology for MIL-HDBK-217 "Reliability Prediction of Electronic Equipment," the widely used approach since 1995.
 
217Plus implements the models presented in the "Handbook of 217Plus™ Reliability Prediction Models".
 
The 217 Plus standard considers:
Quantities
Asjustment Factors
Year of Manufacture
Duty Cycle
Cycling Rate
Ambient Temperatures - Operational and Non-operational
And other part specific variables
The goal of the model is to estimate the "rate of occurrence of failure" and accelerants of a component's primary failure mechanisms within an acceptable degree of accuracy.
 
The types of components that the standard covers are:
Diodes
Capacitors
Integrated Circuits, Plastic Encapsulated
Integrated Circuits, Hermetic
Inductors
Connectors
Transformers
Optoelectronic Devices
Relays
Thyristors
Switches

There are two primary elements to 217 Plus, component library prediction models and system level models. A system failure rate estimate is first made by using the component models to estimate the failure rate of each component. These failure rates are then summed to estimate the system failure rate. This is the traditional process used for most reliability predictions. This estimate is then modified in accordance with system level factors, which account for non-component, or system level,effects.
The goal of a model is to estimate the "rate of occurrence of failure" and accelerants of a component's primary failure mechanisms within an acceptable degree of accuracy. Towards this end, the models should be adequately sensitive to operating scenarios and stresses, so that they allow the user the ability to perform tradeoff analysis among these variables. For example, the basic premise of the 217Plus models is that they have predicted failure rates for operating periods, non-operating periods and cycling. As a result, the user can perform tradeoff analysys amongst duty cycle, cycling rate, and other variables.
Therefore, the purpose of 217Plus handbook is to publish the mathematical models used to perform a reliability prediction and assessment in accordance with its methodology. The basis ofr the 217Plus methodology is the components reliability models, which estimate a system's reliability by summing the predicted failure rates of the constituent components in the system.

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Download 217 Plus Reliability Prediction Software RAM Commander
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