Search results
Results from the WOW.Com Content Network
Failure mode and effects analysis (FMEA; often written with "failure modes" in plural) is the process of reviewing as many components, assemblies, and subsystems as possible to identify potential failure modes in a system and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system ...
The basic failure rate is usually fed into the FMECA from a failure rate prediction based on MIL–HDBK–217, PRISM, RIAC 217Plus, or a similar model. The failure mode ratio may be taken from a database source such as RAC FMD–97.
An FMEDA can predict failure rates per defined failure modes. For Functional Safety applications the IEC 61508 failure modes (safe, dangerous, annunciation, and no effect) are used. These failure rate numbers can be converted into the alternative failure modes from the automotive functional safety standard, ISO 26262.
The failure mode where the switch is stuck in the open position is denominated the safe failure mode, whereas the stuck closed failure mode is denominated the dangerous failure mode. The likelihood of occurrence of a dangerous or safe failure may differ and is a function of several variables in the construction and design of a component.
Often by the time the failure rate data are available, the devices under study have become obsolete. Due to this drawback, failure-rate prediction methods have been developed. These methods may be used on newly designed devices to predict the device's failure rates and failure modes. Two approaches have become well known, Cycle Testing and FMEDA.
An approach to the design and development of reliable product to prevent failure, based on the knowledge of root cause failure mechanisms. The Physics of Failure (PoF) concept is based on the understanding of the relationships between requirements and the physical characteristics of the product and their variation in the manufacturing processes ...
The force of mortality () can be interpreted as the conditional density of failure at age x, while f(x) is the unconditional density of failure at age x. [1] The unconditional density of failure at age x is the product of the probability of survival to age x , and the conditional density of failure at age x , given survival to age x .
The Common Mode Analysis (CMA) looks at the redundant critical components to find failure modes which can cause all to fail at about the same time. Software is always included in this analysis as well as looking for manufacturing errors or "bad lot" components. A failure such as a bad resistor in all flight control computers would be addressed ...