Performing DOE for Defect Reduction

Lean Six Sigma and process excellence leaders are often asked to “remove defects” from products and processes. This can be quite a challenge! Lou Johnson, senior Minitab technical trainer and mentor, has some tips that might help if you’re faced with this situation. I had the chance to talk with Lou, and here’s what he shared with me about how to first approach a DOE.

How to Approach a DOE

Before jumping into a Design of Experiment (DOE) for defect reduction, Lou suggests stepping back and thinking first about what issue is likely causing the problem. If you need help thinking about what might be causing the defects, here is a list of common problems:

• High common cause variation
• A noise variable
• Lack of basic process understanding
• A one-time process change
• Out-of-control process conditions
• A single off-target process step

After pinpointing the likely cause, it will be easier to design your experiment accordingly. But what if you are already immersed in your DOE? For tips from Lou to help you along the way, check out these past posts that outline how to keep your DOE from turning D.O.A.:

Four Tips for Making Sure Your DOE isn’t D.O.A.

Four More Tips for Making Sure Your DOE isn’t D.O.A.

Upcoming Sessions at the Lean and Six Sigma World Conference

If you’re headed to the upcoming Lean and Six Sigma World Conference in San Diego, be sure to catch Lou’s session, “Design of Experiment for Defect Reduction” on February 22 at 8:45 a.m. He’ll talk more about his approach for DOE and illustrate it with several real-world case studies.

Fellow Minitab Blogger Joel Smith will highlight Measurement Systems Analysis (MSA) with examples from Olympic judging in his session at the same conference, which will take place on February 22 at 8:10 a.m. Check the conference program for room assignments: http://www.leanandsixsigma.org/

Of possible interest:

Olympic Judging: Fair or Biased?