It is common for people to learn how machines work and how to operate them. If the pieces from the production line do not meet the quality standard, the operator corrects the machine and tool parameters according to experience. Or if the car body part is not well painted, additional human work is required, which again, according to experience, corrects the defective work of the robot.
With Industry 4.0, where processes are digitized, AI does the machine management. As the concept of machine learning suggests, machines themselves understand processes and adjust their parameters according to their surroundings.