Perform Accelerated Life Testing Data Analysis on External Data Source

With the Synthesis API, you can leverage the ALTA analysis engine to perform accelerated life testing data analysis on an external data source. In this tutorial, you will use the API to create an ALTA data set and analyze it using a single stress model.

Note that this tutorial is for demonstration purposes only; it doesn't take efficiency into account and doesn't include any exception handling.

Tutorial: Accelerated Life Testing Data Analysis
This example demonstrates how to use the Synthesis API to analyze the following ALTA data set and obtain an estimate of the B10 life (i.e., time at which reliability is equal to 90%). A discussion of the example follows.

The VBA version of the code sample is available here.

VB.NET SynthesisAPI Module1 Main ADS ALTADataSet ADS.AddStressDefinition(,,300) ADS.AddFailure(245, 1, 353) ADS.AddFailure(110, 1, 373) ADS.AddFailure(180, 1, 373) ADS.AddFailure(200, 1, 373) ADS.AddFailure(50, 1, 393) ADS.AddFailure(70, 1, 393) ADS.AddFailure(88, 1, 393) ADS.AddFailure(112, 1, 393) ADS.AddFailure(140, 1, 393) ADS.AddFailure(160, 1, 393) ADS.AddSuspension(250, 5, 353) ADS.AddSuspension(250, 3, 373) ADS.AnalysisSettings.ModelType = ALTASolverModel.Arrhenius ADS.AnalysisSettings.Distribution = ALTASolverDistribution.Weibull ADS.Calculate r Double r = ADS.FittedModel.Time(.90) MsgBox( & r)

Discussion
The ALTADataSet class represents an ALTA data sheet for accelerated life testing data analysis. The class contains all the methods and properties that allow you to define a data set and fit a life-stress relationship and distribution to the data.

ADS ALTADataSet

Use the AddStressDefinition method to define the name and use stress level of the stress.

ADS.AddStressDefinition(,,300)

The data set can contain failures, suspensions or interval data. The following example shows how to use the AddFailure method to define failures and the AddSuspension method to define suspensions.

ADS.AddFailure(245, 1, 353) ADS.AddFailure(110, 1, 373) ADS.AddFailure(180, 1, 373) ADS.AddFailure(200, 1, 373) ADS.AddFailure(50, 1, 393) ADS.AddFailure(70, 1, 393) ADS.AddFailure(88, 1, 393) ADS.AddFailure(112, 1, 393) ADS.AddFailure(140, 1, 393) ADS.AddFailure(160, 1, 393) ADS.AddSuspension(250, 5, 353) ADS.AddSuspension(250, 3, 373)

The  property stores a reference to the ALTAAnalysisOptions object, which represents the analysis settings of the data set (i.e., settings that you might find in an ALTA folio's control panel). In this example, we use the property to change some of the attributes of the object.

ADS.AnalysisSettings.ModelType = ALTASolverModel.Arrhenius ADS.AnalysisSettings.Distribution = ALTASolverDistribution.Weibull

Use the Calculate method to analyze the data set.

ADS.Calculate

The  property gets the cModel object that represents the fitted model of the accelerated life testing data analysis. From the model, you can calculate useful metrics such as reliability, failure rate, mean time, etc. In this example, we use the cModel.Time method to calculate the B10 life.

r Double r = ADS.FittedModel.Time(.90) MsgBox( & r)