Introduction to Reliability Engineering & Accelerated Testing

Basic topics in Reliability Engineering are presented with a focus on developing test plans for meeting reliability targets and mitigating risk.  After an introduction to basic reliability concepts and reliability statistics, the course shifts to methods for demonstrating reliability using success-based and test-to-failure strategies.  Life data analysis (i.e., Weibull analysis) is presented along with a brief tutorial of Weibull++ software for performing this analysis. Reliability confidence bounds are introduced along with their impact on test plans and customer reliability statements.  Finally, a number of accelerated testing methods are introduced.

Topics Addressed:

• Bathtub curve, theoretical and actual
• Stress vs strength interference and test severity
• Product design life
• Mean time to failure (MTTF)
• Reliability functions, failure rate, cumulative distribution function (CDF), probability density function (PDF)
• Weibull, lognormal and exponential probability distributions
• Reliability block diagrams (RBD), serial and parallel systems
• Success testing strategies, sample size
• Lipson equality
• Life data analysis and parameter estimation
• Weibull++ primer (ReliaSoft)
• One and two-sided Confidence bounds
• Interpreting reliability specifications
• Accelerated life testing (ALT)
• Arrhenius, inverse power models
• Coffin Manson
• Step stress testing
• Cumulative damage
• HALT and HASS

Target Audience:

Reliability engineers, validation engineers, product development engineers, test engineers, and managers of these disciplines. 

Delivery Method:

The training is designed to be interactive and conversational and is delivered at the client’s location or delivered remotely*.  A number of in-class exercises are included to practice and reinforce the concepts.   Bound training materials are provided to each class participant.  Weibull++ software will be introduced and used for some of the exercises; demo licenses are provided if needed.

* Remote delivery options include six 2-hour sessions (best) or four 3-hour sessions.  “In class” exercises are assigned as HW between sessions.

Expected Outcomes: 

At the conclusion of this training, class participants will be able to:

• Understand the life cycle of a product family in the field by way of the bathtub curve
• Understand the factors that influence the selection of warranty period and product design life
• Create a test plan to meet a reliability specification
• Make trade-offs in sample size vs test duration for a success-based test
• Conduct a basic life data analysis and make inferences using Weibull++
• Recognize 1-sided vs 2-sided confidence bounds and how they effect a reliability test plan
• Select an appropriate confidence bound for your application
• Understand the most common methods to quantitatively and qualitatively accelerate a test
• Design a basic ALT (accelerated life test)
• Create and interpret customer and internal reliability specifications and identify ambiguities and shortcomings if they exist