When automation is used in present-day technological systems, it is often viewed as mainly an engineering concern. Automation was from the beginning introduced to improve the precision, stability, and speed of functions. At present, automation is used either to improve the efficiency of processes or to reduce the risk attributed to human failures. Historically, automation has gradually removed the operator from the process, leading to a loss of ability to control. The classical automation principles, the left-over principle and the comparison principle, both assume that human functions can be replaced by technology with few adverse effects although experience shows that such is not the case. A contemporary alternative is to consider automation from the perspective of the joint system, and to use automation to enhance the system's ability to maintain control of the process. It is argued that automation should be looked at as a socio-technical intervention that directly and indirectly affects human work.