If only I was allowed to talk openly about the specific problems I and my fellow product engineers solved in the semiconductor industry. Let's just say that the setting of a single knob can make the difference between a fab that produces millions of dollars of profit and one that produces millions of parts that are broken and will eventually be scrapped (hopefully before they are sold to customers as part of their cell phones.)
There's a legend about the Intel shipping clerk who single-handedly destroyed a sizeable percentage of his fab's output by being too diligent. He wanted to make sure the company wasn't being shortchanged, so when a box of wafers arrived from the silicon supplier he would open the box, carefully count out the wafers into a pile on his dusty desk, then put them back in the box and send them on into the fab.
Human environments are filled with dust, salt, and oils. When I was trying to finish my Ph.D. -- which required me to build some semiconductor lasers that were reliable enough to be tested more than once -- I eventually reached a mental state where I was so focused on cleanliness that I felt vaguely uncomfortable touching anything, including objects in my own home, without wearing gloves.
There's a legend about the Intel shipping clerk who single-handedly destroyed a sizeable percentage of his fab's output by being too diligent. He wanted to make sure the company wasn't being shortchanged, so when a box of wafers arrived from the silicon supplier he would open the box, carefully count out the wafers into a pile on his dusty desk, then put them back in the box and send them on into the fab.