Accelerated Testing
for predicting and improving product reliability

Instructor: Dr. Wayne Nelson

Many products last for years under normal use conditions. However, product tests must quickly yield reliable information for management and engineering decisions. Accelerated testing quickly yields such information. Test specimens are subjected to higher than normal levels of temperature, voltage, humidity, vibration, etc., and fail much sooner. Then a physical-statistical model is fitted to the early failure data, yielding estimates of product reliability under normal use conditions, including the failure rate, the population percentage failing on warranty or during design life, the mean time to failure, etc. This course shows how to measure and improve the reliability of diverse products.

Benefits

You will learn how to use the latest methods to successfully:

• Determine test purposes.
• Accelerate tests through overstress, high-usage rate, termination of the test before all specimens fail, specimen design, degradation, cycling, etc.
• Plan efficient tests that yield the most accurate product information for the allotted test time, cost, and constraints.
• Model and understand how product life or degradation depends on the accelerating stresses and on design, manufacturing, materials, and operating variables – thereby learning how to improve product reliability.
• Analyze data with simple and informative plots to estimate reliability and to assess the data and presumed model.
• Analyze data with a mix of failure modes 1) to estimate product reliability at a use condition when all failure modes act or 2) to predict reliability if some failure modes were eliminated through proposed design or manufacturing changes.
• Compare designs, manufacturing methods, vendors, materials, etc., with respect to their effect on product reliability.
• Analyze data with modern computer programs that fit complex models to data and provide estimates and corresponding confidence limits, which indicate the accuracy of the estimates.

Who should attend?

This course will benefit engineers, statisticians, and others working in product development, reliability, testing, manufacturing, procurement, and data analysis. You will learn to plan efficient accelerated tests and to accurately estimate product reliability and improve reliability using test data. To benefit fully, you need a working knowledge of a basic Statistics course.

Applications

The methods are applied to a variety of products including:

• Electronics, including microprocessors, semiconductors, solid-state devices, conductors, encapsulants, connections, and capacitors.
• Metal components undergoing fatigue, creep, creep-rupture, and corrosion.
• Electrical insulations and dielectrics in cables, motors, capacitors, electronics, transformers, etc.
• Ceramics, plastics, composites, and other materials.
• Pharmaceuticals, foods, paints and protective coatings, rubber and elastic materials, and chemicals.
• Munitions, propellants, and other energetics.

You will apply the methods to actual applications, including your own data, which you are asked to bring.

Text

The course text Accelerated Testing: Statistical Models, Test Plans, and Data Analyses, published by Wiley (2004), was written by Wayne Nelson. The textbook, plotting papers, computer program information, and other reference materials are furnished at the course.

Instructor