When facing yet another field issue with a high price tag, my Chief Technical Officer asked me, “How do we get more predictive so we can identify and prevent these failures from occurring in the future?”  Similarly, I had a friend who was trying to optimize a key customer feature of a future product.  He ran robustness experimentation considering over 40 noise and control factors that the team had brainstormed.  And yet, when field trials started, the device had several failures of unknown cause.  Of the more than 40 factors that they had considered during brainstorming, they missed the noise factor that was triggering these failures.  I’ll turn to you and ask the same question:  How do we get better at predicting future failures and preventing them from occurring?  If we had infinite knowledge, we could see these failures before they occurred.

We can learn more from our failures than we can from our successes.  This isn’t just a good rule for us to live by personally but is applicable to the products that we design and manufacture.  In my experience, the all-important step that is short-changed in “learning from our failures” is “learning”—not just getting to the root cause in order to solve the problem but to understanding the gaps that exist in our current design and manufacturing requirements and practices that allowed the failure to spill into the field.   Identifying these gaps is the key to future failure prevention.  In this installment, I’m going to highlight how Weibull Analysis (a reliability tool when used in the time domain) of module field failures can be used to identify the holes in our design or manufacturing requirements or processes.