Module 8 Introduction to Accelerated Life Testing (ALT)

Lesson M08-06

Duration: 67 minutes

Time Varying Stress Tests (e.g. Step stress) are introduced.  The idea of the cumulative damage model is discussed.  An example of setting up and analyzing a time-varying stress tests is presented in Reliasoft. Several exercises are available including both single and multiple time-varying stresses as well as specifying a time-varying use stress.

Reliability Reference Textbook – Section 10, Pages 59-62

Module 8 Introduction to Accelerated Life Testing (ALT)

Lesson M08-05

Duration: 61 minutes

Two-stress situations are introduced.  The concept of factor interactions is discussed.  Models for handling two different stresses are presented. These include the Temperature-Humidity Model, Temperature-Non Thermal Model, Generalized Eyring Model, Proportional Hazards Model, and the General Log-Linear Model.  Several exercises are included to practice using these models.  

Reliability Reference Textbook – Section 10, Pages 48-58

Module 8 Introduction to Accelerated Life Testing (ALT)

Lesson M08-04

Duration: 27 minutes

You have an opportunity to practice analyzing ALT data, developing models, and obtaining reliability estimates with several different datasets.  

Module 8 Introduction to Accelerated Life Testing (ALT)

Lesson M08-03

Duration: 49 minutes

Here we present the main steps involved in analyzing data from an ALT.  We present an example using Reliasoft to illustrate the data setup, model fitting, graphical output, and statistical output

Reliability Reference Textbook – Section 10, Pages 26-46

Module 8 Introduction to Accelerated Life Testing (ALT)

Lesson M08-02

Duration: 23 minutes

Different structural models are presented for single stress problems.  These include the Arrhenius, Eyring and Inverse Power Law models.  Guidelines for using these models are provided.  

Reliability Reference Textbook – Section 10, Pages 14-25

Module 8 Introduction to Accelerated Life Testing (ALT)

Lesson M08-01

In this lesson we introduce Accelerated Life Testing and discuss some different types of ALTs including Highly Accelerated Life Tests (HALT), Highly Accelerated Stress Screening (HASS), and Quantitative ALTs.  Type of stress loadings (e.g. constant, strep stress, etc.) are reviewed.  The parts (stochastic and structural) of the overall ALT model are presented and Acceleration Factors are defined.

Reliability Reference Textbook – Section 10, Pages 1-13

Module 7 Reliability Test Planning

Lesson M07-07

Duration: 9 minutes

A special case of the reliability demonstration test plan is covered.  This occurs when the testing time is the same time at which we desire to demonstrate reliability.  In this instance, fewer assumptions are required, although the plan may not be feasible from a sample size perspective.  We end the lesson with a discussion of some practical issues with demonstration testing. 

Module 7 Reliability Test Planning

Lesson M07-06

Duration: 9 minutes

The exercise to follow allows you to practice specifying demonstration testing plans to achieve the goal of the test.  

Module 7 Reliability Test Planning

Lesson M07-05

Duration: 48 minutes

Reliability Demonstration tests allow us to show that the reliability requirements have been achieved and this may be done even without actual failures.  The types and options in demonstration testing are described.  The steps required and a demonstration of an example in Reliasoft are presented.  We also discuss a tool which enables us to consider the chances for failing the test (due to lack of statistical power), even if the population meets the reliability requirements.  This may be helpful in selecting the best plan.  

Reliability Reference Textbook – Section 8, Pages 29-35

Module 7 Reliability Test Planning

Lesson M07-04

Duration: 29 minutes

This exercise provides an opportunity to practice calculating the sample size necessary to perform a reliability estimation test based on the assumptions provided.  We also demonstrate the use of Simulation in Reliasoft to perform Estimation Test Planning.  

Module 7 Reliability Test Planning

Lesson M07-03

Duration: 28 minutes

Planning should be done before initiating reliability estimation tests.  This ensures that the test is likely to produce estimates with adequate precision to be useful.  Here, we review the steps for planning reliability estimation tests and discuss the factors that will influence the sample size determination.  We walk through an example in Reliasoft to illustrate the iterative planning process to arrive at approximate sample sizes that will be required. 

Reliability Reference Textbook – Section 8, Pages 24-28

Module 7 Reliability Test Planning

Lesson M07-02

Duration: 6 minutes

Here, the purpose of test planning is described.  To prepare for the next lesson, this lesson 2 introduces sub-types of right censoring (Fixed Time -Type I and Fixed Failure – Type II).  

Reliability Reference Textbook – Section 8, Pages 1-24

Module 7 Reliability Test Planning

Lesson M07-01

Duration: 18 minutes

The first lesson discusses the types of reliability tests and general planning for these tests.  We emphasize the importance of testing to failure rather than testing to success with limited sample sizes.  

Module 6 Analysis of Field Data — Warranty Forecasting

Lesson M06-04

Duration: 10 minutes

Reliability Reference Textbook – Section 13, Pages 2-11

The following exercise gives you an opportunity to analyze a set of field data and produce a warranty forecast. 

Module 6 Analysis of Field Data — Warranty Forecasting

Lesson M06-03

Duration: 43 minutes

Now, we review the Reliasoft functionality that is available for producing a warranty forecast through a demonstration.