The worker knows “his” machine – every humming, rattling, and squeaking noise, and every blinking light. If anything changes, the machine is immediately readjusted or the maintenance department is informed. Workflows often remain unchanged for years. Even the slightest deviation from the machine’s usual routine might indicate that something is wrong – for example, that a machine component has become loose or defective, or that a quality problem has developed in a downstream processing step, and therefore, any specified tolerances are no longer correct. The worker knows every idiosyncrasy of his machine. This can also lead to monotony. Safety is a central issue, because the high complexity of the machines makes them increasingly confusing and often conceals sources of danger. When changes are made in production – for example, changeover to a new product – the worker usually has to be retrained. New task – new know- how.