Reliability / Weibull Analysis

Course Overview

This course teaches participants the fundamental concepts and methods needed to analyze and understand reliability data. The course focuses on the proper application of statistical methods to model failure data, estimate quantities of interest for both components and systems, and make predictions. Knowledge of basic algebra is helpful. Computer software is utilized, although an understanding of underlying concepts and methods is stressed.

Objectives:

  • Understand reliability concepts and unique aspects of reliability data
  • Understand underlying probability and statistical concepts for reliability analysis
  • Develop competency in the modeling and analysis of time-to-failure data
  • Understand reliability metrics and how to estimate and report them
  • Handle Multiple Failure Modes
  • Estimate reliability of subsystems and systems
  • Become aware of system reliability activities such as Reliability Block diagramming, Reliability importance, and Reliability allocation
  • Determine if reliability specifications are met (at specified confidence level) or whether design improvements are required
  • Develop competency in the planning of reliability tests (sample sizes)
  • Develop reliability demonstration test plans (testing time vs. number of units tradeoffs)
  • Analyze existing warranty data to predict future returns

Reliability/Weibull Analysis Seminar Content

  • Reliability Concepts and Reliability Data
  • Reliability in Product and Process Development
  • Unique Characteristics of Reliability Data
  • Censored Data

Probability and Statistics Concepts

  • Basic Probability Concepts
  • Probability Distributions (e.g. Weibull, Lognormal, etc.)
  • Probability Distribution Functions
  • CDF and Reliability Functions
  • Reliability Metrics: Hazard Rate, Mean Time to Failure, Percentiles
  • Conditional Reliability & Applications
  • Assessing & Selecting Models (Distributions) for Failure Data
  • Probability Plotting with and without Censored Data
  • Identifying the Best Distribution(s)
  • Criteria for Comparing Model Fits
  • Estimation of Reliability Characteristics
  • Estimation Methods (Maximum Likelihood, Rank Regression)
  • Reliability/Weibull Analysis (and other distributions)
  • Precision of Estimates/Confidence Intervals
  • Handling Multiple Failure Modes
  • Comparing Reliability of Different Designs/Groups

Introduction to Reliability of Systems

  • Series Systems
  • Parallel Systems
  • K-out-of-n Systems
  • Complex Systems
  • Introduction to System Modeling, Reliability Allocation

Reliability Test Planning

  • Test planning regimes
  • Reliability Estimation Test Plans
  • Reliability Demonstration Test Plans
  • Sample Sizes for Estimation and Demonstration Test Plans
  • Sample Size / Testing Time Trade-offs

Analysis of Warranty Data

  • Data Setup
  • Identifying Models for Failure Data
  • Forecasting Future Warranty Returns
  • Non-Homogeneous Production Periods

Design for Reliability Overview

Introduction to Advanced Topics / Other Topics

  • Accelerated Life Testing
  • Stress/Strength Analysis
  • Introduction to Repairable Systems Analysis