Is Your Data Telling You the Truth? How Confirmation...

> TL;DR: When you already 'know' the root cause, your brain will find data to confirm it and ignore data that contradicts it — the best 8D investigators hunt for disconfirming evidence, not supporting evidence. Have you noticed a really interesting pattern? On day one of an 8D, everyone already knows what the root cause is. Then everything from D2 to D4 is just a ritual — not to find the truth, but to build a case for the conclusion that was already decided. This isn't analysis. This is shooting the arrow first and drawing the target around where it landed. We just package it professionally — fishbone diagram, 5-Why, statistical tools — but underneath it's all about legitimizing a predetermined position. I did this too when I was younger. It embarrasses me now. The customer said "it must be a material issue," so I dove into the incoming inspection reports. After digging through three months of data, I finally found one batch where a parameter was off by 0.1%. I grabbed it like a treasure and declared in D4: "Material batch anomaly caused the failure." Customer was satisfied, supplier got penalized, case closed. Everyone happy. But over a year...