Many years ago, I ran a site that used several 100 K kg of a toxic, explosive and flammable gas. They were just about to hit their permitted levels of emissions

Many years ago, I ran a site that used several 100 K kg of a toxic, explosive and flammable gas. They were just about to hit their permitted levels of emissions and didn't know why. I sat with the team and said to them that everything in the past was done with the knowledge available at the time - water under the bridge. We set ourselves small goals and worked our way through the system from beginning to end, doing little experiments to prove/disprove our assumptions. Over the timescale of months, the attitudes changed, and my engineers began to say things like "we were wrong when we did this/that". We had just one rule - if the data shows that a previously made assumption was wrong, accept it and fix it. We went from ~1000 kg emissions down to the ppb level over time. One of the best teams I had worked with, and a great memory.