Accelerated Life Testing (ALT) is required to evaluate product reliability for parts that need to perform well for long periods.  Due to low failure rates at use conditions, parts must be tested at high stress levels in order to generate failures in a reasonable amount of time. Devices requiring such reliability analyses include medical devices, semiconductor circuits, aviation equipment and more. See how to analyze accelerated test data to predict lifetimes at use conditions for both single and multiple constant stresses tests, along with ramped stress tests.  A safe operating area using contour plots will also be described.      

This webinar covers: Fit Life by X, Parametric Survival, Step Stress.

Suggested Prerequisites: Learning Library -  Accelerated Life Testing (Fit Life by X)

See how to:

• Use Accelerated life testing (ALT) as a practical way to estimate lifetimes at use conditions.
• Access a variety of models (Arrhenius, power law, etc.) to make predictions.
• Identify a safe operating area (SOA) for multiple stresses, which can provide a reliability map of product lifetime.
• Employ a step stress approach to save a lot of time vs. constant stress.
• Access degradation models that allow you to extrapolate the failure times, get an idea what the reliability will be.

Definitions

• Arrhenius Equation or Model - Describes the relation between the rate of reaction and temperature for many physical and chemical processes. The equation relates the dependence of the degradation mechanism on absolute temperature (T) and therefore, the time to failure.  Time to fail ~ exp(Ea/T) where Ea is the activation energy. Can be used to estimate reliability parameters as temperature changes.
• Power Law Model - Equation that gives the dependence between failure time and the stress, where the failure time is a function of the stress to some exponent (or power). Time to fail ~ stress^n where n is an exponent.
• Censoring - Censoring a datapoint means that the datapoint is excluded as a failure time but still included in the analysis as the operating time of the part. Right censoring – stress on the part was stopped before the part failed. Interval censoring – failure of the part occurred within some known time interval. Left censoring – the part failed at some point before the start of the test. Left censoring is not common in industrial experiments.