By now you've got a whole system on paper. Every conveyor sized, every speed set, every controls layer drawn. And every number on it came out of a calculator that assumed a perfect world: a rigid box, a new belt running at exactly the commanded speed, clean air, every roller present and spinning. The real world honors none of that. This part is where you find out which of your numbers survive contact with a slipping belt, a shifted load, a maintenance team of one, and a person reaching into the line to clear a jam at 2 AM. You prove the rate. You prove it stays up. You prove it's safe for the people around it. The calculator was never the answer. It did the arithmetic fast so you could spend your judgment on the part that actually decides whether this system works. That judgment is the whole job, and this is where you sign your name to it.
The calculator got you here. Judgment decides whether you sign it. This is Part VI.