DOE Simplified: Practical Tools for Effective Experimentation, Third Edition

Table of Contents

Basic Statistics for DOE
The "X" Factors
Does Normal Distribution Ring Your Bell?
Descriptive Statistics: Mean and Lean
Confidence Intervals Help You Manage Expectations
Graphical Tests Provide Quick Check for Normality
Practice Problems

Simple Comparative Experiments
The F-Test Simplified
A Dicey Situation: Making Sure They Are Fair
Catching Cheaters with a Simple Comparative Experiment
Blocking Out Known Sources of Variation
Practice Problems

Two-Level Factorial Design
Two-Level Factorial Design: As Simple as Making Microwave Popcorn
How to Plot and Interpret Interactions
Protect Yourself with Analysis of Variance (ANOVA)
Modeling Your Responses with Predictive Equations
Diagnosing Residuals to Validate Statistical Assumptions
Practice Problems
Appendix: How to Make a More Useful Pareto Chart

Dealing with Nonnormality via Response Transformations
Skating on Thin Ice
Log Transformation Saves the Data
Choosing the Right Transformation
Practice Problem

Fractional Factorials
Example of Fractional Factorial at Its Finest
Potential Confusion Caused by Aliasing in Lower Resolution Factorials
Plackett–Burman Designs
Irregular Fractions Provide a Clearer View
Practice Problem

Getting the Most from Minimal-Run Designs
Minimal-Resolution Design: The Dancing Raisin Experiment
Complete Foldover of Resolution III Design
Single-Factor Foldover
Choose a High-Resolution Design to Reduce Aliasing Problems
Practice Problems
Appendix: Minimum-Run Designs for Screening

General Multilevel Categoric Factorials
Putting a Spring in Your Step: A General Factorial Design on Spring Toys
How to Analyze Unreplicated General Factorials
Practice Problems
Appendix: Half-Normal Plot for General Factorial Designs
Response Surface Methods for Optimization
Center Points Detect Curvature in Confetti
Augmenting to a Central Composite Design (CCD)
Finding Your Sweet Spot for Multiple Responses

Mixture Design
Two-Component Mixture Design: Good as Gold
Three-Component Design: Teeny Beany Experiment

Back to the Basics: The Keys to Good DOE
A Four-Step Process for Designing a Good Experiment
A Case Study Showing Application of the Four-Step Design Process
Appendix: Details on Power
     Managing Expectations for What the Experiment Might Reveal
     Increase the Range of Your Factors
     Decrease the Noise (σ) in Your System
     Accept Greater Risk of Type I Error (α)
     Select a Better and/or Bigger Design

Split-Plot Designs to Accommodate Hard-to-Change Factors
How Split Plots Naturally Emerged for Agricultural Field Tests
Applying a Split Plot to Save Time Making Paper Helicopters
Trade-Off of Power for Convenience When Restricting Randomization
One More Split Plot Example: A Heavy-Duty Industrial One

Practice Experiments
Practice Experiment #1: Breaking Paper Clips
Practice Experiment #2: Hand–Eye Coordination
Other Fun Ideas for Practice Experiments
     Ball in Funnel
     Flight of the Balsa Buzzard
     Paper Airplanes
     Impact Craters

Appendix 1
Two-Tailed t-Table
F-Table for 10%
F-Table for 5%
F-Table for 1%
F-Table for 0.1%

Appendix 2
Four-Factor Screening and Characterization Designs
     Screening Main Effects in 8 Runs
     Screening Design Layout
     Alias Structure
     Characterizing Interactions with 12 Runs
     Characterization Design Layout
     Alias Structure for Factorial Two-Factor Interaction Model
     Alias Structure for Factorial Main Effect Model
Five-Factor Screening and Characterization Designs
     Screening Main Effects in 12 Runs
     Screening Design Layout
     Alias Structure
     Characterizing Interactions with 16 Runs
     Design Layout
     Alias Structure for Factorial Two-Factor Interaction (2FI) Model
Six-Factor Screening and Characterization Designs
     Screening Main Effects in 14 Runs
     Screening Design Layout
     Alias Structure
     Characterizing Interactions with 22 Runs
     Design Layout
     Alias Structure for Factorial Two-Factor Interaction (2FI) Model
Seven-Factor Screening and Characterization Designs
     Screening Design Layout
     Alias Structure
     Characterizing Interactions with 30 Runs
     Design Layout
     Alias Structure for Factorial Two-Factor Interaction (2FI) Model

Glossary
Statistical Symbols
Terms

Recommended Readings
Textbooks
Case Study Articles

Index