Braverman, H. (1974). Labor and Monopoly Capital: The Degredation of Work in the Twentieth Century,. New York, Monthly Review Press.
Chapter 9: Machinery
The key element in the evolution of machinery is not its size, compexity, or speed, but the manner in which it's operations are controlled. The increasing amount of control built into the machines means more control is removed from the laborer. Intially evolution of machinery became more specialized (and with it the laborers), but now they are becoming more multi-purpose.
"Before the human capacity to control machinery can be transformed into its opposite, a series of special conditions must be met with have nothing to do with the physical character of the machine. The machine must be the property not of the producer...but of an alien power. The interests of the two must be antagonistic. The manner in which labor is deployed around the machinery...must be dictated not by the human needs of the producers but by the special needs of those who own the machinery." It also requires a labor force dulled into conforming to the needs of these owners -- fit for machine servitude. Thus machinery becomes not a source of freedom but of enslavement, not of mastery but helplessness..."
Machinery offers to management the opportunity to do by wholly mechanical means that which it had previously attempted to do by organizational and disciplinary means".
In machine shops the introduction of numerical control allowed management to replace skilled craftsman with lesser skilled "monitors".
The development is a headlong rush toward capital accumulation where the social effects are largely disregarded. Each advance in productivity shrinks the number of truly productive workers.