Template:ALTA Standard Folio Plot Example

ALTA Standard Folio Plot Type Example

This example illustrates the different plots that can be generated in ALTA. Consider to the following accelerated testing data.

Time Failed (hr)	Temperature (K)
248	406
456	406
528	406
731	406
813	406
164	416
176	416
289	416
319	416
340	416
543	416
92	426
105	426
155	426
184	426
219	426
235	426

The data was analyzed using the Arrhenius relationship and the Weibull distribution. The next figure shows the ALTA folio with the results of the analysis.

Given this analysis the following plots can be generated in ALTA.

1. Use Level Probability Plot

The use level probability plot uses the selected model to extrapolate the times-to-failure at the observed (accelerated) stress level to the specified use stress level. In this example the use temperature was set at 356K. The data points are then reordered and plotted, along with the overall solution based on the Arrhenius-Weibull model at 356K.

2. Probability Plot

The probability plot presents the data at the entered individual stress levels (406K, 416K and 426K). In addition, the use stress level line, based on the estimated parameters of the Arrhenius-Weibull model and the specified stress level of 356K, is plotted. The y-axis represents unreliability and the x-axis represents time.